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ultimatepp/bazaar/PixRaster/lib/blend.c
micio db3a6a0036 Start of Leptonica library support 
git-svn-id: svn://ultimatepp.org/upp/trunk@1554 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2009-09-06 15:49:56 +00:00

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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
- This software is distributed in the hope that it will be
- useful, but with NO WARRANTY OF ANY KIND.
- No author or distributor accepts responsibility to anyone for the
- consequences of using this software, or for whether it serves any
- particular purpose or works at all, unless he or she says so in
- writing. Everyone is granted permission to copy, modify and
- redistribute this source code, for commercial or non-commercial
- purposes, with the following restrictions: (1) the origin of this
- source code must not be misrepresented; (2) modified versions must
- be plainly marked as such; and (3) this notice may not be removed
- or altered from any source or modified source distribution.
*====================================================================*/
/*
* blend.c
*
* Blending two images that are not colormapped
* PIX *pixBlend()
* PIX *pixBlendMask()
* PIX *pixBlendGray()
* PIX *pixBlendColor()
* PIX *pixBlendColorByChannel()
* PIX *pixBlendGrayAdapt()
* static l_int32 blendComponents()
* PIX *pixFadeWithGray()
* PIX *pixBlendHardLight()
* static l_int32 blendHardLightComponents()
*
* Blending two colormapped images
* l_int32 pixBlendCmap()
*
* Coloring "gray" pixels
* l_int32 pixColorGray()
*
* Adjusting one or more colors to a target color
* PIX *pixSnapColor()
* PIX *pixSnapColorCmap()
*
* In blending operations a new pix is produced where typically
* a subset of pixels in src1 are changed by the set of pixels
* in src2, when src2 is located in a given position relative
* to src1. This is similar to rasterop, except that the
* blending operations we allow are more complex, and typically
* result in dest pixels that are a linear combination of two
* pixels, such as src1 and its inverse. I find it convenient
* to think of src2 as the "blender" (the one that takes the action)
* and src1 as the "blendee" (the one that changes).
*
* Blending works best when src1 is 8 or 32 bpp. We also allow
* src1 to be colormapped, but the colormap is removed before blending,
* so if src1 is colormapped, we can't allow in-place blending.
*
* Because src2 is typically smaller than src1, we can implement by
* clipping src2 to src1 and then transforming some of the dest
* pixels that are under the support of src2. In practice, we
* do the clipping in the inner pixel loop. For grayscale and
* color src2, we also allow a simple form of transparency, where
* pixels of a particular value in src2 are transparent; for those pixels,
* no blending is done.
*
* The blending functions are categorized by the depth of src2,
* the blender, and not that of src1, the blendee.
*
* - If src2 is 1 bpp, we can do one of three things:
* (1) L_BLEND_WITH_INVERSE: Blend a given fraction of src1 with its
* inverse color for those pixels in src2 that are fg (ON),
* and leave the dest pixels unchanged for pixels in src2 that
* are bg (OFF).
* (2) L_BLEND_TO_WHITE: Fade the src1 pixels toward white by a
* given fraction for those pixels in src2 that are fg (ON),
* and leave the dest pixels unchanged for pixels in src2 that
* are bg (OFF).
* (3) L_BLEND_TO_BLACK: Fade the src1 pixels toward black by a
* given fraction for those pixels in src2 that are fg (ON),
* and leave the dest pixels unchanged for pixels in src2 that
* are bg (OFF).
* The blending function is pixBlendMask().
*
* - If src2 is 8 bpp grayscale, we can do one of two things
* (but see pixFadeWithGray() below):
* (1) L_BLEND_GRAY: If src1 is 8 bpp, mix the two values, using
* a fraction of src2 and (1 - fraction) of src1.
* If src1 is 32 bpp (rgb), mix the fraction of src2 with
* each of the color components in src1.
* (2) L_BLEND_GRAY_WITH_INVERSE: Use the grayscale value in src2
* to determine how much of the inverse of a src1 pixel is
* to be combined with the pixel value. The input fraction
* further acts to scale the change in the src1 pixel.
* The blending function is pixBlendGray().
*
* - If src2 is color, we blend a given fraction of src2 with
* src1. If src1 is 8 bpp, the resulting image is 32 bpp.
* The blending function is pixBlendColor().
*
* - For all three blending functions -- pixBlendMask(), pixBlendGray()
* and pixBlendColor() -- you can apply the blender to the blendee
* either in-place or generating a new pix. For the in-place
* operation, this requires that the depth of the resulting pix
* must equal that of the input pixs1.
*
* - We remove colormaps from src1 and src2 before blending.
* Any quantization would have to be done after blending.
*
* We include another function, pixFadeWithGray(), that blends
* a gray or color src1 with a gray src2. It does one of these things:
* (1) L_BLEND_TO_WHITE: Fade the src1 pixels toward white by
* a number times the value in src2.
* (2) L_BLEND_TO_BLACK: Fade the src1 pixels toward black by
* a number times the value in src2.
*
* Also included is a generalization of the so-called "hard light"
* blending: pixBlendHardLight(). We generalize by allowing a fraction < 1.0
* of the blender to be admixed with the blendee. The standard function
* does full mixing.
*/
#include <stdio.h>
#include <stdlib.h>
#include "allheaders.h"
static l_int32 blendComponents(l_int32 a, l_int32 b, l_float32 fract);
static l_int32 blendHardLightComponents(l_int32 a, l_int32 b, l_float32 fract);
/*-------------------------------------------------------------*
* Pixel blending *
*-------------------------------------------------------------*/
/*!
* pixBlend()
*
* Input: pixs1 (blendee)
* pixs2 (blender; typ. smaller)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1; can be < 0)
* fract (blending fraction)
* Return: 0 if OK; 1 on error
*
* Note: simple top-level interface. For more flexibility, call
* directly into pixBlendMask(), etc.
*/
PIX *
pixBlend(PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract)
{
l_int32 w1, h1, d1, d2;
BOX *box;
PIX *pixc, *pixt, *pixd;
PROCNAME("pixBlend");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, NULL);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, NULL);
/* check relative depths */
d1 = pixGetDepth(pixs1);
d2 = pixGetDepth(pixs2);
if (d1 == 1 && d2 > 1)
return (PIX *)ERROR_PTR("mixing gray or color with 1 bpp",
procName, NULL);
/* remove colormap from pixs2 if necessary */
pixt = pixRemoveColormap(pixs2, REMOVE_CMAP_BASED_ON_SRC);
d2 = pixGetDepth(pixt);
/* Check if pixs2 is clipped by its position with respect
* to pixs1; if so, clip it and redefine x and y if necessary.
* This actually isn't necessary, as the specific blending
* functions do the clipping directly in the pixel loop
* over pixs2, but it's included here to show how it can
* easily be done on pixs2 first. */
w1 = pixGetWidth(pixs1);
h1 = pixGetHeight(pixs1);
box = boxCreate(-x, -y, w1, h1); /* box of pixs1 relative to pixs2 */
pixc = pixClipRectangle(pixt, box, NULL);
boxDestroy(&box);
if (!pixc) {
L_WARNING("box doesn't overlap pix", procName);
return NULL;
}
x = L_MAX(0, x);
y = L_MAX(0, y);
if (d2 == 1)
pixd = pixBlendMask(NULL, pixs1, pixc, x, y, fract,
L_BLEND_WITH_INVERSE);
else if (d2 == 8)
pixd = pixBlendGray(NULL, pixs1, pixc, x, y, fract,
L_BLEND_GRAY, 0, 0);
else /* d2 == 32 */
pixd = pixBlendColor(NULL, pixs1, pixc, x, y, fract, 0, 0);
pixDestroy(&pixc);
pixDestroy(&pixt);
return pixd;
}
/*!
* pixBlendMask()
*
* Input: pixd (<optional>; either NULL or equal to pixs1 for in-place)
* pixs1 (blendee; depth > 1)
* pixs2 (blender; typ. smaller in size than pixs1)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1; can be < 0)
* fract (blending fraction)
* type (L_BLEND_WITH_INVERSE, L_BLEND_TO_WHITE, L_BLEND_TO_BLACK)
* Return: pixd if OK; pixs1 on error
*
* Notes:
* (1) pixs2 must be 1 bpp
* (2) Clipping of pixs2 to pixs1 is done in the inner pixel loop.
* (3) If pixs1 has a colormap, it is removed.
* (4) For inplace operation, call it this way:
* pixBlendMask(pixs1, pixs1, pixs2, ...)
* (5) For generating a new pixd:
* pixd = pixBlendMask(NULL, pixs1, pixs2, ...)
* (6) Only call in-place if pixs1 does not have a colormap.
*/
PIX *
pixBlendMask(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract,
l_int32 type)
{
l_int32 i, j, d, wc, hc, w, h, wplc;
l_int32 val, rval, gval, bval;
l_uint32 pixval;
l_uint32 *linec, *datac;
PIX *pixc, *pixt1, *pixt2;
PROCNAME("pixBlendMask");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
if (pixGetDepth(pixs1) == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (pixGetDepth(pixs2) != 1)
return (PIX *)ERROR_PTR("pixs2 not 1 bpp", procName, pixd);
if (pixd == pixs1 && pixGetColormap(pixs1))
return (PIX *)ERROR_PTR("inplace; pixs1 has colormap", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("pixd must be NULL or pixs1", procName, pixd);
if (fract < 0.0 || fract > 1.0) {
L_WARNING("fract must be in [0.0, 1.0]; setting to 0.5", procName);
fract = 0.5;
}
if (type != L_BLEND_WITH_INVERSE && type != L_BLEND_TO_WHITE &&
type != L_BLEND_TO_BLACK) {
L_WARNING("invalid blend type; setting to L_BLEND_WITH_INVERSE",
procName);
type = L_BLEND_WITH_INVERSE;
}
/* If pixd != NULL, we know that it is equal to pixs1 and
* that pixs1 does not have a colormap, so that an in-place operation
* can be done. Otherwise, remove colormap from pixs1 if
* it exists and unpack to at least 8 bpp if necessary,
* to do the blending on a new pix. */
if (!pixd) {
pixt1 = pixRemoveColormap(pixs1, REMOVE_CMAP_BASED_ON_SRC);
if (pixGetDepth(pixt1) < 8)
pixt2 = pixConvertTo8(pixt1, FALSE);
else
pixt2 = pixClone(pixt1);
pixd = pixCopy(NULL, pixt2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
pixGetDimensions(pixd, &w, &h, &d); /* d must be either 8 or 32 bpp */
pixc = pixClone(pixs2);
wc = pixGetWidth(pixc);
hc = pixGetHeight(pixc);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
/* Check limits for src1, in case clipping was not done. */
switch (type)
{
case L_BLEND_WITH_INVERSE:
/*
* The core logic for this blending is:
* p --> (1 - f) * p + f * (1 - p)
* where p is a normalized value: p = pixval / 255.
* Thus,
* p --> p + f * (1 - 2 * p)
*/
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
bval = GET_DATA_BIT(linec, j);
if (bval) {
switch (d)
{
case 8:
pixGetPixel(pixd, x + j, y + i, &pixval);
val = (l_int32)(pixval + fract * (255 - 2 * pixval));
pixSetPixel(pixd, x + j, y + i, val);
break;
case 32:
pixGetPixel(pixd, x + j, y + i, &pixval);
extractRGBValues(pixval, &rval, &gval, &bval);
rval = (l_int32)(rval + fract * (255 - 2 * rval));
gval = (l_int32)(gval + fract * (255 - 2 * gval));
bval = (l_int32)(bval + fract * (255 - 2 * bval));
composeRGBPixel(rval, gval, bval, &pixval);
pixSetPixel(pixd, x + j, y + i, pixval);
break;
default:
L_WARNING("d neither 8 nor 32 bpp; no blend", procName);
}
}
}
}
break;
case L_BLEND_TO_WHITE:
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
bval = GET_DATA_BIT(linec, j);
if (bval) {
switch (d)
{
case 8:
pixGetPixel(pixd, x + j, y + i, &pixval);
val = (l_int32)(pixval + fract * (255 - pixval));
pixSetPixel(pixd, x + j, y + i, val);
break;
case 32:
pixGetPixel(pixd, x + j, y + i, &pixval);
extractRGBValues(pixval, &rval, &gval, &bval);
rval = (l_int32)(rval + fract * (255 - rval));
gval = (l_int32)(gval + fract * (255 - gval));
bval = (l_int32)(bval + fract * (255 - bval));
composeRGBPixel(rval, gval, bval, &pixval);
pixSetPixel(pixd, x + j, y + i, pixval);
break;
default:
L_WARNING("d neither 8 nor 32 bpp; no blend", procName);
}
}
}
}
break;
case L_BLEND_TO_BLACK:
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
bval = GET_DATA_BIT(linec, j);
if (bval) {
switch (d)
{
case 8:
pixGetPixel(pixd, x + j, y + i, &pixval);
val = (l_int32)((1. - fract) * pixval);
pixSetPixel(pixd, x + j, y + i, val);
break;
case 32:
pixGetPixel(pixd, x + j, y + i, &pixval);
extractRGBValues(pixval, &rval, &gval, &bval);
rval = (l_int32)((1. - fract) * rval);
gval = (l_int32)((1. - fract) * gval);
bval = (l_int32)((1. - fract) * bval);
composeRGBPixel(rval, gval, bval, &pixval);
pixSetPixel(pixd, x + j, y + i, pixval);
break;
default:
L_WARNING("d neither 8 nor 32 bpp; no blend", procName);
}
}
}
}
break;
default:
L_WARNING("invalid binary mask blend type", procName);
break;
}
pixDestroy(&pixc);
return pixd;
}
/*!
* pixBlendGray()
*
* Input: pixd (<optional>; either NULL or equal to pixs1 for in-place)
* pixs1 (blendee; depth > 1)
* pixs2 (blender, 8 bpp; typ. smaller in size than pixs1)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1; can be < 0)
* fract (blending fraction)
* type (L_BLEND_GRAY, L_BLEND_GRAY_WITH_INVERSE)
* transparent (1 to use transparency; 0 otherwise)
* transpix (pixel grayval in pixs2 that is to be transparent)
* Return: pixd if OK; pixs1 on error
*
* Notes:
* (1) pixs2 must be 8 bpp, and have no colormap.
* (2) Clipping of pixs2 to pixs1 is done in the inner pixel loop.
* (3) If pixs1 has a colormap, it is removed.
* (4) If pixs1 has depth < 8, it is unpacked to generate a 8 bpp pix.
* (5) For inplace operation, call it this way:
* pixBlendGray(pixs1, pixs1, pixs2, ...)
* (6) For generating a new pixd:
* pixd = pixBlendGray(NULL, pixs1, pixs2, ...)
* (7) Only call in-place if pixs1 does not have a colormap;
* otherwise it is an error.
* (8) If transparent = 0, the blending fraction (fract) is
* applied equally to all pixels.
* (9) If transparent = 1, all pixels of value transpix (typically
* either 0 or 0xff) in pixs2 are transparent in the blend.
* (10) After processing pixs1, it is either 8 bpp or 32 bpp:
* - if 8 bpp, the fraction of pixs2 is mixed with pixs1.
* - if 32 bpp, each component of pixs1 is mixed with
* the same fraction of pixs2.
* (11) For L_BLEND_GRAY_WITH_INVERSE, the white values of the blendee
* (cval == 255 in the code below) result in a delta of 0.
* Thus, these pixels are intrinsically transparent!
* The "pivot" value of the src, at which no blending occurs, is
* 128. Compare with the adaptive pivot in pixBlendGrayAdapt().
*/
PIX *
pixBlendGray(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract,
l_int32 type,
l_int32 transparent,
l_uint32 transpix)
{
l_int32 i, j, d, wc, hc, w, h, wplc, wpld, delta;
l_int32 ival, irval, igval, ibval, cval, dval;
l_uint32 val32;
l_uint32 *linec, *lined, *datac, *datad;
PIX *pixc, *pixt1, *pixt2;
PROCNAME("pixBlendGray");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
if (pixGetDepth(pixs1) == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (pixGetDepth(pixs2) != 8)
return (PIX *)ERROR_PTR("pixs2 not 8 bpp", procName, pixd);
if (pixGetColormap(pixs2))
return (PIX *)ERROR_PTR("pixs2 has a colormap", procName, pixd);
if (pixd == pixs1 && pixGetColormap(pixs1))
return (PIX *)ERROR_PTR("can't do in-place with cmap", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("pixd must be NULL or pixs1", procName, pixd);
if (fract < 0.0 || fract > 1.0) {
L_WARNING("fract must be in [0.0, 1.0]; setting to 0.5", procName);
fract = 0.5;
}
if (type != L_BLEND_GRAY && type != L_BLEND_GRAY_WITH_INVERSE) {
L_WARNING("invalid blend type; setting to L_BLEND_GRAY", procName);
type = L_BLEND_GRAY;
}
/* If pixd != NULL, we know that it is equal to pixs1 and
* that pixs1 does not have a colormap, so that an in-place operation
* can be done. Otherwise, remove colormap from pixs1 if
* it exists and unpack to at least 8 bpp if necessary,
* to do the blending on a new pix. */
if (!pixd) {
pixt1 = pixRemoveColormap(pixs1, REMOVE_CMAP_BASED_ON_SRC);
if (pixGetDepth(pixt1) < 8)
pixt2 = pixConvertTo8(pixt1, FALSE);
else
pixt2 = pixClone(pixt1);
pixd = pixCopy(NULL, pixt2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
pixGetDimensions(pixd, &w, &h, &d); /* 8 or 32 bpp */
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
pixc = pixClone(pixs2);
pixGetDimensions(pixc, &wc, &hc, NULL);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
/* check limits for src1, in case clipping was not done */
if (type == L_BLEND_GRAY) {
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
switch (d)
{
case 8:
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval = GET_DATA_BYTE(linec, j);
if (transparent == 0 ||
(transparent != 0 && cval != transpix)) {
dval = GET_DATA_BYTE(lined, j + x);
ival = (l_int32)((1. - fract) * dval + fract * cval);
SET_DATA_BYTE(lined, j + x, ival);
}
}
break;
case 32:
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval = GET_DATA_BYTE(linec, j);
if (transparent == 0 ||
(transparent != 0 && cval != transpix)) {
val32 = *(lined + j + x);
extractRGBValues(val32, &irval, &igval, &ibval);
irval = (l_int32)((1. - fract) * irval + fract * cval);
igval = (l_int32)((1. - fract) * igval + fract * cval);
ibval = (l_int32)((1. - fract) * ibval + fract * cval);
composeRGBPixel(irval, igval, ibval, &val32);
*(lined + j + x) = val32;
}
}
break;
default:
break; /* shouldn't happen */
}
}
}
else { /* L_BLEND_GRAY_WITH_INVERSE */
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
switch (d)
{
case 8:
/*
* For 8 bpp, the dest pix is shifted by a signed amount
* proportional to the distance from 128 (the pivot value),
* and to the darkness of src2. If the dest is darker
* than 128, it becomes lighter, and v.v.
* The basic logic is:
* d --> d + f * (0.5 - d) * (1 - c)
* where d and c are normalized pixel values for src1 and
* src2, respectively, with normalization to 255.
*/
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval = GET_DATA_BYTE(linec, j);
if (transparent == 0 ||
(transparent != 0 && cval != transpix)) {
ival = GET_DATA_BYTE(lined, j + x);
delta = (128 - ival) * (255 - cval) / 256;
ival += (l_int32)(fract * delta + 0.5);
SET_DATA_BYTE(lined, j + x, ival);
}
}
break;
case 32:
/* Each component is shifted by the same formula for 8 bpp */
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval = GET_DATA_BYTE(linec, j);
if (transparent == 0 ||
(transparent != 0 && cval != transpix)) {
val32 = *(lined + j + x);
extractRGBValues(val32, &irval, &igval, &ibval);
delta = (128 - irval) * (255 - cval) / 256;
irval += (l_int32)(fract * delta + 0.5);
delta = (128 - igval) * (255 - cval) / 256;
igval += (l_int32)(fract * delta + 0.5);
delta = (128 - ibval) * (255 - cval) / 256;
ibval += (l_int32)(fract * delta + 0.5);
composeRGBPixel(irval, igval, ibval, &val32);
*(lined + j + x) = val32;
}
}
break;
default:
break; /* shouldn't happen */
}
}
}
pixDestroy(&pixc);
return pixd;
}
/*!
* pixBlendColor()
*
* Input: pixd (<optional>; either NULL or equal to pixs1 for in-place)
* pixs1 (blendee; depth > 1)
* pixs2 (blender, 32 bpp; typ. smaller in size than pixs1)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1)
* fract (blending fraction)
* transparent (1 to use transparency; 0 otherwise)
* transpix (pixel color in pixs2 that is to be transparent)
* Return: pixd if OK; pixs1 on error
*
* Notes:
* (1) pixs2 must be 32 bpp, and have no colormap.
* (2) Clipping of pixs2 to pixs1 is done in the inner pixel loop.
* (3) If pixs1 has a colormap, it is removed to generate a 32 bpp pix.
* (4) If pixs1 has depth < 32, it is unpacked to generate a 32 bpp pix.
* (5) For inplace operation, call it this way:
* pixBlendColor(pixs1, pixs1, pixs2, ...)
* (6) For generating a new pixd:
* pixd = pixBlendColor(NULL, pixs1, pixs2, ...)
* (7) Only call in-place if pixs1 is 32 bpp; otherwise it is an error.
* (8) If transparent = 0, the blending fraction (fract) is
* applied equally to all pixels.
* (9) If transparent = 1, all pixels of value transpix (typically
* either 0 or 0xffffff00) in pixs2 are transparent in the blend.
*/
PIX *
pixBlendColor(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract,
l_int32 transparent,
l_uint32 transpix)
{
l_int32 i, j, wc, hc, w, h, wplc, wpld;
l_int32 rval, gval, bval, rcval, gcval, bcval;
l_uint32 cval32, val32;
l_uint32 *linec, *lined, *datac, *datad;
PIX *pixc, *pixt1, *pixt2;
PROCNAME("pixBlendColor");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
if (pixGetDepth(pixs1) == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (pixGetDepth(pixs2) != 32)
return (PIX *)ERROR_PTR("pixs2 not 32 bpp", procName, pixd);
if (pixd == pixs1 && pixGetDepth(pixs1) != 32)
return (PIX *)ERROR_PTR("inplace; pixs1 not 32 bpp", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("pixd must be NULL or pixs1", procName, pixd);
if (fract < 0.0 || fract > 1.0) {
L_WARNING("fract must be in [0.0, 1.0]; setting to 0.5", procName);
fract = 0.5;
}
/* If pixd != NULL, we know that it is equal to pixs1 and
* that pixs1 is 32 bpp rgb, so that an in-place operation
* can be done. Otherwise, remove colormap from pixs1 if
* it exists and unpack to 32 bpp if necessary, to do the
* blending on a new 32 bpp Pix. */
if (!pixd) {
pixt1 = pixRemoveColormap(pixs1, REMOVE_CMAP_TO_FULL_COLOR);
if (pixGetDepth(pixt1) < 32)
pixt2 = pixConvertTo32(pixt1);
else
pixt2 = pixClone(pixt1);
pixd = pixCopy(NULL, pixt2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
pixGetDimensions(pixd, &w, &h, NULL);
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
pixc = pixClone(pixs2);
pixGetDimensions(pixc, &wc, &hc, NULL);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
/* check limits for src1, in case clipping was not done */
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval32 = *(linec + j);
if (transparent == 0 ||
(transparent != 0 &&
((cval32 & 0xffffff00) != (transpix & 0xffffff00)))) {
val32 = *(lined + j + x);
extractRGBValues(cval32, &rcval, &gcval, &bcval);
extractRGBValues(val32, &rval, &gval, &bval);
rval = (l_int32)((1. - fract) * rval + fract * rcval);
gval = (l_int32)((1. - fract) * gval + fract * gcval);
bval = (l_int32)((1. - fract) * bval + fract * bcval);
composeRGBPixel(rval, gval, bval, &val32);
*(lined + j + x) = val32;
}
}
}
pixDestroy(&pixc);
return pixd;
}
/*
* pixBlendColorByChannel()
*
* This is an extended version of pixBlendColor. All parameters have the
* same meaning except it takes one mixing fraction per channel, and the
* mixing fraction may be < 0 or > 1, in which case, the min or max of two
* images are taken. More specifically,
*
* for a = pixs1[i], b = pixs2[i]:
* frac < 0.0 --> min(a, b)
* frac > 1.0 --> max(a, b)
* else --> (1-frac)*a + frac*b
* frac == 0 --> a
* frac == 1 --> b
*
* Notes:
* (1) See usage notes in pixBlendColor()
* (2) pixBlendColor() would be equivalent to
* pixBlendColorChannel(..., fract, fract, fract, ...);
* at a small cost of efficiency.
*/
PIX *
pixBlendColorByChannel(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 rfract,
l_float32 gfract,
l_float32 bfract,
l_int32 transparent,
l_uint32 transpix)
{
l_int32 i, j, wc, hc, w, h, wplc, wpld;
l_int32 rval, gval, bval, rcval, gcval, bcval;
l_uint32 cval32, val32;
l_uint32 *linec, *lined, *datac, *datad;
PIX *pixc, *pixt1, *pixt2;
PROCNAME("pixBlendColorByChannel");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
if (pixGetDepth(pixs1) == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (pixGetDepth(pixs2) != 32)
return (PIX *)ERROR_PTR("pixs2 not 32 bpp", procName, pixd);
if (pixd == pixs1 && pixGetDepth(pixs1) != 32)
return (PIX *)ERROR_PTR("inplace; pixs1 not 32 bpp", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("pixd must be NULL or pixs1", procName, pixd);
/* If pixd != NULL, we know that it is equal to pixs1 and
* that pixs1 is 32 bpp rgb, so that an in-place operation
* can be done. Otherwise, remove colormap from pixs1 if
* it exists and unpack to 32 bpp if necessary, to do the
* blending on a new 32 bpp Pix. */
if (!pixd) {
pixt1 = pixRemoveColormap(pixs1, REMOVE_CMAP_TO_FULL_COLOR);
if (pixGetDepth(pixt1) < 32)
pixt2 = pixConvertTo32(pixt1);
else
pixt2 = pixClone(pixt1);
pixd = pixCopy(NULL, pixt2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
pixGetDimensions(pixd, &w, &h, NULL);
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
pixc = pixClone(pixs2);
pixGetDimensions(pixc, &wc, &hc, NULL);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
/* Check limits for src1, in case clipping was not done */
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval32 = *(linec + j);
if (transparent == 0 ||
(transparent != 0 &&
((cval32 & 0xffffff00) != (transpix & 0xffffff00)))) {
val32 = *(lined + j + x);
extractRGBValues(cval32, &rcval, &gcval, &bcval);
extractRGBValues(val32, &rval, &gval, &bval);
rval = blendComponents(rval, rcval, rfract);
gval = blendComponents(gval, gcval, gfract);
bval = blendComponents(bval, bcval, bfract);
composeRGBPixel(rval, gval, bval, &val32);
*(lined + j + x) = val32;
}
}
}
pixDestroy(&pixc);
return pixd;
}
static l_int32
blendComponents(l_int32 a,
l_int32 b,
l_float32 fract)
{
if (fract < 0.)
return ((a < b) ? a : b);
if (fract > 1.)
return ((a > b) ? a : b);
return (l_int32)((1. - fract) * a + fract * b);
}
/*!
* pixBlendGrayAdapt()
*
* Input: pixd (<optional>; either NULL or equal to pixs1 for in-place)
* pixs1 (blendee; depth > 1)
* pixs2 (blender, 8 bpp; typ. smaller in size than pixs1)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1; can be < 0)
* fract (blending fraction)
* shift (>= 0 but <= 128: shift of zero blend value from
* median source; use -1 for default value; )
* Return: pixd if OK; pixs1 on error
*
* Notes:
* (1) pixs2 must be 8 bpp, and have no colormap.
* (2) Clipping of pixs2 to pixs1 is done in the inner pixel loop.
* (3) If pixs1 has a colormap, it is removed.
* (4) If pixs1 has depth < 8, it is unpacked to generate a 8 bpp pix.
* (5) For inplace operation, call it this way:
* pixBlendGray(pixs1, pixs1, pixs2, ...)
* For generating a new pixd:
* pixd = pixBlendGray(NULL, pixs1, pixs2, ...)
* Only call in-place if pixs1 does not have a colormap;
* otherwise it is an error.
* (6) This does a blend with inverse. Whereas in pixGlendGray(), the
* zero blend point is where the blendee pixel is 128, here
* the zero blend point is found adaptively, with respect to the
* median of the blendee region. If the median is < 128,
* the zero blend point is found from
* median + shift.
* Otherwise, if the median >= 128, the zero blend point is
* median - shift.
* The purpose of shifting the zero blend point away from the
* median is to prevent a situation in pixBlendGray() where
* the median is 128 and the blender is not visible.
* The default value of shift is 64.
* (7) After processing pixs1, it is either 8 bpp or 32 bpp:
* - if 8 bpp, the fraction of pixs2 is mixed with pixs1.
* - if 32 bpp, each component of pixs1 is mixed with
* the same fraction of pixs2.
* (8) The darker the blender, the more it mixes with the blendee.
* A blender value of 0 has maximum mixing; a value of 255
* has no mixing and hence is transparent.
*/
PIX *
pixBlendGrayAdapt(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract,
l_int32 shift)
{
l_int32 i, j, d, wc, hc, w, h, wplc, wpld, delta, overlap;
l_int32 rval, gval, bval, cval, dval, mval, median, pivot;
l_uint32 val32;
l_uint32 *linec, *lined, *datac, *datad;
l_float32 fmedian, factor;
BOX *box, *boxt;
PIX *pixc, *pixt1, *pixt2;
PROCNAME("pixBlendGrayAdapt");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
if (pixGetDepth(pixs1) == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (pixGetDepth(pixs2) != 8)
return (PIX *)ERROR_PTR("pixs2 not 8 bpp", procName, pixd);
if (pixGetColormap(pixs2))
return (PIX *)ERROR_PTR("pixs2 has a colormap", procName, pixd);
if (pixd == pixs1 && pixGetColormap(pixs1))
return (PIX *)ERROR_PTR("can't do in-place with cmap", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("pixd must be NULL or pixs1", procName, pixd);
if (fract < 0.0 || fract > 1.0) {
L_WARNING("fract must be in [0.0, 1.0]; setting to 0.5", procName);
fract = 0.5;
}
if (shift == -1) shift = 64; /* default value */
if (shift < 0 || shift > 127) {
L_WARNING("invalid shift; setting to 64", procName);
shift = 64;
}
/* Test for overlap */
pixGetDimensions(pixs1, &w, &h, NULL);
pixGetDimensions(pixs2, &wc, &hc, NULL);
box = boxCreate(x, y, wc, hc);
boxt = boxCreate(0, 0, w, h);
boxIntersects(box, boxt, &overlap);
boxDestroy(&boxt);
if (!overlap) {
boxDestroy(&box);
return (PIX *)ERROR_PTR("no image overlap", procName, pixd);
}
/* If pixd != NULL, we know that it is equal to pixs1 and
* that pixs1 does not have a colormap, so that an in-place operation
* can be done. Otherwise, remove colormap from pixs1 if
* it exists and unpack to at least 8 bpp if necessary,
* to do the blending on a new pix. */
if (!pixd) {
pixt1 = pixRemoveColormap(pixs1, REMOVE_CMAP_BASED_ON_SRC);
if (pixGetDepth(pixt1) < 8)
pixt2 = pixConvertTo8(pixt1, FALSE);
else
pixt2 = pixClone(pixt1);
pixd = pixCopy(NULL, pixt2);
pixDestroy(&pixt1);
pixDestroy(&pixt2);
}
/* Get the median value in the region of blending */
pixt1 = pixClipRectangle(pixd, box, NULL);
pixt2 = pixConvertTo8(pixt1, 0);
pixGetRankValueMasked(pixt2, NULL, 0, 0, 1, 0.5, &fmedian, NULL);
median = (l_int32)(fmedian + 0.5);
if (median < 128)
pivot = median + shift;
else
pivot = median - shift;
/* L_INFO_INT2("median = %d, pivot = %d", procName, median, pivot); */
pixDestroy(&pixt1);
pixDestroy(&pixt2);
boxDestroy(&box);
/* Process over src2; clip to src1. */
d = pixGetDepth(pixd);
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
pixc = pixClone(pixs2);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
switch (d)
{
case 8:
/*
* For 8 bpp, the dest pix is shifted by an amount
* proportional to the distance from the pivot value,
* and to the darkness of src2. In no situation will it
* pass the pivot value in intensity.
* The basic logic is:
* d --> d + f * (np - d) * (1 - c)
* where np, d and c are normalized pixel values for
* the pivot, src1 and src2, respectively, with normalization
* to 255.
*/
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
dval = GET_DATA_BYTE(lined, j + x);
cval = GET_DATA_BYTE(linec, j);
delta = (pivot - dval) * (255 - cval) / 256;
dval += (l_int32)(fract * delta + 0.5);
SET_DATA_BYTE(lined, j + x, dval);
}
break;
case 32:
/*
* For 32 bpp, the dest pix is shifted by an amount
* proportional to the max component distance from the
* pivot value, and to the darkness of src2. Each component
* is shifted by the same fraction, either up or down,
* depending on the shift direction (which is toward the
* pivot). The basic logic for the red component is:
* r --> r + f * (np - m) * (1 - c) * (r / m)
* where np, r, m and c are normalized pixel values for
* the pivot, the r component of src1, the max component
* of src1, and src2, respectively, again with normalization
* to 255. Likewise for the green and blue components.
*/
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
cval = GET_DATA_BYTE(linec, j);
val32 = *(lined + j + x);
extractRGBValues(val32, &rval, &gval, &bval);
mval = L_MAX(rval, gval);
mval = L_MAX(mval, bval);
mval = L_MAX(mval, 1);
delta = (pivot - mval) * (255 - cval) / 256;
factor = fract * delta / mval;
rval += (l_int32)(factor * rval + 0.5);
gval += (l_int32)(factor * gval + 0.5);
bval += (l_int32)(factor * bval + 0.5);
composeRGBPixel(rval, gval, bval, &val32);
*(lined + j + x) = val32;
}
break;
default:
break; /* shouldn't happen */
}
}
pixDestroy(&pixc);
return pixd;
}
/*!
* pixFadeWithGray()
*
* Input: pixs (colormapped or 8 bpp or 32 bpp)
* pixb (8 bpp blender)
* factor (multiplicative factor to apply to blender value)
* type (L_BLEND_TO_WHITE, L_BLEND_TO_BLACK)
* Return: pixd, or null on error
*
* Notes:
* (1) This function combines two pix aligned to the UL corner; they
* need not be the same size.
* (2) Each pixel in pixb is multiplied by 'factor' divided by 255, and
* clipped to the range [0 ... 1]. This gives the fade fraction
* to be appied to pixs. Fade either to white (L_BLEND_TO_WHITE)
* or to black (L_BLEND_TO_BLACK).
*/
PIX *
pixFadeWithGray(PIX *pixs,
PIX *pixb,
l_float32 factor,
l_int32 type)
{
l_int32 i, j, w, h, d, wb, hb, db, wd, hd, wplb, wpld;
l_int32 valb, vald, nvald, rval, gval, bval, nrval, ngval, nbval;
l_float32 nfactor, fract;
l_uint32 val32, nval32;
l_uint32 *lined, *datad, *lineb, *datab;
PIX *pixd;
PIXCMAP *cmap;
PROCNAME("pixFadeWithGray");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, NULL);
if (!pixb)
return (PIX *)ERROR_PTR("pixb not defined", procName, NULL);
cmap = pixGetColormap(pixs);
d = pixGetDepth(pixs);
if (d < 8 && !cmap)
return (PIX *)ERROR_PTR("pixs not cmapped and < 8bpp", procName, NULL);
pixGetDimensions(pixb, &wb, &hb, &db);
if (db != 8)
return (PIX *)ERROR_PTR("pixb not 8bpp", procName, NULL);
if (type != L_BLEND_TO_WHITE && type != L_BLEND_TO_BLACK)
return (PIX *)ERROR_PTR("invalid fade type", procName, NULL);
if (cmap)
pixd = pixRemoveColormap(pixs, REMOVE_CMAP_BASED_ON_SRC);
else
pixd = pixCopy(NULL, pixs);
pixGetDimensions(pixd, &wd, &hd, &d);
w = L_MIN(wb, wd);
h = L_MIN(hb, hd);
datad = pixGetData(pixd);
wpld = pixGetWpl(pixd);
datab = pixGetData(pixb);
wplb = pixGetWpl(pixb);
nfactor = factor / 255.;
for (i = 0; i < h; i++) {
lineb = datab + i * wplb;
lined = datad + i * wpld;
for (j = 0; j < w; j++) {
valb = GET_DATA_BYTE(lineb, j);
fract = nfactor * (l_float32)valb;
fract = L_MIN(fract, 1.0);
if (d == 8) {
vald = GET_DATA_BYTE(lined, j);
if (type == L_BLEND_TO_WHITE)
nvald = vald + (l_int32)(fract * (255. - (l_float32)vald));
else /* L_BLEND_TO_BLACK */
nvald = vald - (l_int32)(fract * (l_float32)vald);
SET_DATA_BYTE(lined, j, nvald);
}
else { /* d == 32 */
val32 = lined[j];
extractRGBValues(val32, &rval, &gval, &bval);
if (type == L_BLEND_TO_WHITE) {
nrval = rval + (l_int32)(fract * (255. - (l_float32)rval));
ngval = gval + (l_int32)(fract * (255. - (l_float32)gval));
nbval = bval + (l_int32)(fract * (255. - (l_float32)bval));
}
else {
nrval = rval - (l_int32)(fract * (l_float32)rval);
ngval = gval - (l_int32)(fract * (l_float32)gval);
nbval = bval - (l_int32)(fract * (l_float32)bval);
}
composeRGBPixel(nrval, ngval, nbval, &nval32);
lined[j] = nval32;
}
}
}
return pixd;
}
/*
* pixBlendHardLight()
*
* Input: pixd (<optional>; either NULL or equal to pixs1 for in-place)
* pixs1 (blendee; depth > 1, may be cmapped)
* pixs2 (blender, 8 or 32 bpp; may be colormapped;
* typ. smaller in size than pixs1)
* x,y (origin (UL corner) of pixs2 relative to
* the origin of pixs1)
* fract (blending fraction, or 'opacity factor')
* Return: pixd if OK; pixs1 on error
*
* Notes:
* (1) pixs2 must be 8 or 32 bpp; either may have a colormap.
* (2) Clipping of pixs2 to pixs1 is done in the inner pixel loop.
* (3) Only call in-place if pixs1 is not colormapped.
* (4) If pixs1 has a colormap, it is removed to generate either an
* 8 or 32 bpp pix, depending on the colormap.
* (5) For inplace operation, call it this way:
* pixBlendHardLight(pixs1, pixs1, pixs2, ...)
* (6) For generating a new pixd:
* pixd = pixBlendHardLight(NULL, pixs1, pixs2, ...)
* (7) This is a generalization of the usual hard light blending,
* where fract == 1.0.
* (8) When the opacity factor fract = 1.0, this implements "overlay"
* blending, by swapping pixs1 and pixs2.
* (9) See, e.g.:
* http://www.pegtop.net/delphi/articles/blendmodes/hardlight.htm
* http://www.digitalartform.com/imageArithmetic.htm
* (10) This function was built by Paco Galanes.
*/
PIX *
pixBlendHardLight(PIX *pixd,
PIX *pixs1,
PIX *pixs2,
l_int32 x,
l_int32 y,
l_float32 fract)
{
l_int32 i, j, w, h, d, wc, hc, dc, wplc, wpld;
l_int32 cval, dval, rcval, gcval, bcval, rdval, gdval, bdval;
l_uint32 cval32, dval32;
l_uint32 *linec, *lined, *datac, *datad;
PIX *pixc, *pixt;
PROCNAME("pixBlendHardLight");
if (!pixs1)
return (PIX *)ERROR_PTR("pixs1 not defined", procName, pixd);
if (!pixs2)
return (PIX *)ERROR_PTR("pixs2 not defined", procName, pixd);
pixGetDimensions(pixs1, &w, &h, &d);
pixGetDimensions(pixs2, &wc, &hc, &dc);
if (d == 1)
return (PIX *)ERROR_PTR("pixs1 is 1 bpp", procName, pixd);
if (dc != 8 && dc != 32)
return (PIX *)ERROR_PTR("pixs2 not 8 or 32 bpp", procName, pixd);
if (pixd && (pixd != pixs1))
return (PIX *)ERROR_PTR("inplace and pixd != pixs1", procName, pixd);
if (pixd == pixs1 && pixGetColormap(pixs1))
return (PIX *)ERROR_PTR("inplace and pixs1 cmapped", procName, pixd);
if (pixd && d != 8 && d != 32)
return (PIX *)ERROR_PTR("inplace and not 8 or 32 bpp", procName, pixd);
if (fract < 0.0 || fract > 1.0) {
L_WARNING("fract must be in [0.0, 1.0]; setting to 0.5", procName);
fract = 0.5;
}
/* If pixs2 has a colormap, remove it */
if (pixGetColormap(pixs2))
pixc = pixRemoveColormap(pixs2, REMOVE_CMAP_BASED_ON_SRC);
else
pixc = pixClone(pixs2);
dc = pixGetDepth(pixc);
/* There are 4 cases:
* * pixs1 has or doesn't have a colormap
* * pixc is either 8 or 32 bpp
* In all situations, if pixs has a colormap it must be removed,
* and pixd must have a depth that is equal to or greater than pixc. */
if (dc == 32) {
if (pixGetColormap(pixs1)) /* pixd == NULL */
pixd = pixRemoveColormap(pixs1, REMOVE_CMAP_TO_FULL_COLOR);
else {
if (!pixd)
pixd = pixConvertTo32(pixs1);
else {
pixt = pixConvertTo32(pixs1);
pixCopy(pixd, pixt);
pixDestroy(&pixt);
}
}
d = 32;
} else { /* dc == 8 */
if (pixGetColormap(pixs1)) /* pixd == NULL */
pixd = pixRemoveColormap(pixs1, REMOVE_CMAP_BASED_ON_SRC);
else
pixd = pixCopy(pixd, pixs1);
d = pixGetDepth(pixd);
}
if (!(d == 8 && dc == 8) && /* 3 cases only */
!(d == 32 && dc == 8) &&
!(d == 32 && dc == 32)) {
pixDestroy(&pixc);
return (PIX *)ERROR_PTR("bad! -- invalid depth combo!", procName, pixd);
}
wpld = pixGetWpl(pixd);
datad = pixGetData(pixd);
datac = pixGetData(pixc);
wplc = pixGetWpl(pixc);
for (i = 0; i < hc; i++) {
if (i + y < 0 || i + y >= h) continue;
linec = datac + i * wplc;
lined = datad + (i + y) * wpld;
for (j = 0; j < wc; j++) {
if (j + x < 0 || j + x >= w) continue;
if (d == 8 && dc == 8) {
dval = GET_DATA_BYTE(lined, x + j);
cval = GET_DATA_BYTE(linec, j);
dval = blendHardLightComponents(dval, cval, fract);
SET_DATA_BYTE(lined, x + j, dval);
} else if (d == 32 && dc == 8) {
dval32 = *(lined + x + j);
extractRGBValues(dval32, &rdval, &gdval, &bdval);
cval = GET_DATA_BYTE(linec, j);
rdval = blendHardLightComponents(rdval, cval, fract);
gdval = blendHardLightComponents(gdval, cval, fract);
bdval = blendHardLightComponents(bdval, cval, fract);
composeRGBPixel(rdval, gdval, bdval, &dval32);
*(lined + x + j) = dval32;
} else if (d == 32 && dc == 32) {
dval32 = *(lined + x + j);
extractRGBValues(dval32, &rdval, &gdval, &bdval);
cval32 = *(linec + j);
extractRGBValues(cval32, &rcval, &gcval, &bcval);
rdval = blendHardLightComponents(rdval, rcval, fract);
gdval = blendHardLightComponents(gdval, gcval, fract);
bdval = blendHardLightComponents(bdval, bcval, fract);
composeRGBPixel(rdval, gdval, bdval, &dval32);
*(lined + x + j) = dval32;
}
}
}
pixDestroy(&pixc);
return pixd;
}
/*
* blendHardLightComponents()
* Input: a (8 bpp blendee component)
* b (8 bpp blender component)
* fract (fraction of blending; use 1.0 for usual definition)
* Return: blended 8 bpp component
*/
static l_int32 blendHardLightComponents(l_int32 a,
l_int32 b,
l_float32 fract)
{
if (b < 0x80) {
b = 0x80 - (l_int32)(fract * (0x80 - b));
return (a * b) >> 7;
} else {
b = 0x80 + (l_int32)(fract * (b - 0x80));
return 0xff - (((0xff - b) * (0xff - a)) >> 7);
}
}
/*-------------------------------------------------------------*
* Blending two colormapped images *
*-------------------------------------------------------------*/
/*!
* pixBlendCmap()
*
* Input: pixs (2, 4 or 8 bpp, with colormap)
* pixb (colormapped blender)
* x, y (UL corner of blender relative to pixs)
* sindex (colormap index of pixels in pixs to be changed)
* Return: 0 if OK, 1 on error
*
* Note:
* (1) This function combines two colormaps, and replaces the pixels
* in pixs that have a specified color value with those in pixb.
* (2) sindex must be in the existing colormap; otherwise an
* error is returned. In use, sindex will typically be the index
* for white (255, 255, 255).
* (3) Blender colors that already exist in the colormap are used;
* others are added. If any blender colors cannot be
* stored in the colormap, an error is returned.
* (4) In the implementation, a mapping is generated from each
* original blender colormap index to the corresponding index
* in the expanded colormap for pixs. Then for each pixel in
* pixs with value sindex, and which is covered by a blender pixel,
* the new index corresponding to the blender pixel is substituted
* for sindex.
*/
l_int32
pixBlendCmap(PIX *pixs,
PIX *pixb,
l_int32 x,
l_int32 y,
l_int32 sindex)
{
l_int32 rval, gval, bval;
l_int32 i, j, w, h, d, ncb, wb, hb, wpls;
l_int32 index, val, nadded;
l_int32 lut[256];
l_uint32 pval;
l_uint32 *lines, *datas;
PIXCMAP *cmaps, *cmapb, *cmapsc;
PROCNAME("pixBlendCmap");
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
if (!pixb)
return ERROR_INT("pixb not defined", procName, 1);
if ((cmaps = pixGetColormap(pixs)) == NULL)
return ERROR_INT("no colormap in pixs", procName, 1);
if ((cmapb = pixGetColormap(pixb)) == NULL)
return ERROR_INT("no colormap in pixb", procName, 1);
ncb = pixcmapGetCount(cmapb);
/* Make a copy of cmaps; we'll add to this if necessary
* and substitute at the end if we found there was enough room
* to hold all the new colors. */
cmapsc = pixcmapCopy(cmaps);
pixGetDimensions(pixs, &w, &h, &d);
if (d != 2 && d != 4 && d != 8)
return ERROR_INT("depth not in {2,4,8}", procName, 1);
/* Add new colors if necessary; get mapping array between
* cmaps and cmapb. */
for (i = 0, nadded = 0; i < ncb; i++) {
pixcmapGetColor(cmapb, i, &rval, &gval, &bval);
if (pixcmapGetIndex(cmapsc, rval, gval, bval, &index)) { /* not found */
if (pixcmapAddColor(cmapsc, rval, gval, bval)) {
pixcmapDestroy(&cmapsc);
return ERROR_INT("not enough room in cmaps", procName, 1);
}
lut[i] = pixcmapGetCount(cmapsc) - 1;
nadded++;
}
else
lut[i] = index;
}
/* Replace cmaps if colors have been added. */
if (nadded == 0)
pixcmapDestroy(&cmapsc);
else
pixSetColormap(pixs, cmapsc);
/* Replace each pixel value sindex by mapped colormap index when
* a blender pixel in pixbc overlays it. */
datas = pixGetData(pixs);
wpls = pixGetWpl(pixs);
pixGetDimensions(pixb, &wb, &hb, NULL);
for (i = 0; i < hb; i++) {
if (i + y < 0 || i + y >= h) continue;
lines = datas + (y + i) * wpls;
for (j = 0; j < wb; j++) {
if (j + x < 0 || j + x >= w) continue;
switch (d) {
case 2:
val = GET_DATA_DIBIT(lines, x + j);
if (val == sindex) {
pixGetPixel(pixb, j, i, &pval);
SET_DATA_DIBIT(lines, x + j, lut[pval]);
}
break;
case 4:
val = GET_DATA_QBIT(lines, x + j);
if (val == sindex) {
pixGetPixel(pixb, j, i, &pval);
SET_DATA_QBIT(lines, x + j, lut[pval]);
}
break;
case 8:
val = GET_DATA_BYTE(lines, x + j);
if (val == sindex) {
pixGetPixel(pixb, j, i, &pval);
SET_DATA_BYTE(lines, x + j, lut[pval]);
}
break;
default:
return ERROR_INT("depth not in {2,4,8}", procName, 1);
}
}
}
return 0;
}
/*---------------------------------------------------------------------*
* Coloring "gray" pixels *
*---------------------------------------------------------------------*/
/*!
* pixColorGray()
*
* Input: pixs (rgb or colormapped image)
* box (<optional> region in which to apply color; can be NULL)
* type (L_PAINT_LIGHT, L_PAINT_DARK)
* thresh (average value below/above which pixel is unchanged)
* rval, gval, bval (new color to paint)
* Return: 0 if OK; 1 on error
*
* Note:
* (1) This is an in-place operation.
* (2) If type == L_PAINT_LIGHT, it colorizes non-black pixels,
* preserving antialiasing.
* If type == L_PAINT_DARK, it colorizes non-white pixels,
* preserving antialiasing.
* (3) If box is NULL, applies function to the entire image; otherwise,
* clips the operation to the intersection of the box and pix.
* (4) If colormapped, calls pixColorGrayCmap(), which applies the
* coloring algorithm only to pixels that are strictly gray.
* (5) For RGB, determines a "gray" value by averaging; then uses this
* value, plus the input rgb target, to generate the output
* pixel values.
* (6) thresh is only used for rgb; it is ignored for colormapped pix.
* If type == L_PAINT_LIGHT, use thresh = 0 if all pixels are to
* be colored (black pixels will be unaltered).
* In situations where there are a lot of black pixels,
* setting thresh > 0 will make the function considerably
* more efficient without affecting the final result.
* If type == L_PAINT_DARK, use thresh = 255 if all pixels
* are to be colored (white pixels will be unaltered).
* In situations where there are a lot of white pixels,
* setting thresh < 255 will make the function considerably
* more efficient without affecting the final result.
*/
l_int32
pixColorGray(PIX *pixs,
BOX *box,
l_int32 type,
l_int32 thresh,
l_int32 rval,
l_int32 gval,
l_int32 bval)
{
l_int32 i, j, w, h, d, wpl, x1, x2, y1, y2, bw, bh;
l_int32 nrval, ngval, nbval, aveval;
l_float32 factor;
l_uint32 val32;
l_uint32 *line, *data;
PIXCMAP *cmap;
PROCNAME("pixColorGray");
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
if (!pixs)
return ERROR_INT("pixs not defined", procName, 1);
if (type != L_PAINT_LIGHT && type != L_PAINT_DARK)
return ERROR_INT("invalid type", procName, 1);
cmap = pixGetColormap(pixs);
pixGetDimensions(pixs, &w, &h, &d);
if (!cmap && d != 32)
return ERROR_INT("pixs not cmapped or rgb", procName, 1);
if (cmap)
return pixColorGrayCmap(pixs, box, type, rval, gval, bval);
/* rgb image; check the thresh */
if (type == L_PAINT_LIGHT) { /* thresh should be low */
if (thresh >= 255)
return ERROR_INT("thresh must be < 255; else this is a no-op",
procName, 1);
if (thresh > 127)
L_WARNING("threshold set very high", procName);
}
else { /* type == L_PAINT_DARK; thresh should be high */
if (thresh <= 0)
return ERROR_INT("thresh must be > 0; else this is a no-op",
procName, 1);
if (thresh < 128)
L_WARNING("threshold set very low", procName);
}
if (!box) {
x1 = y1 = 0;
x2 = w;
y2 = h;
}
else {
boxGetGeometry(box, &x1, &y1, &bw, &bh);
x2 = x1 + bw - 1;
y2 = y1 + bh - 1;
}
data = pixGetData(pixs);
wpl = pixGetWpl(pixs);
factor = 1. / 255.;
for (i = y1; i <= y2; i++) {
if (i < 0 || i >= h)
continue;
line = data + i * wpl;
for (j = x1; j <= x2; j++) {
if (j < 0 || j >= w)
continue;
val32 = *(line + j);
aveval = ((val32 >> 24) + ((val32 >> 16) & 0xff) +
((val32 >> 8) & 0xff)) / 3;
if (type == L_PAINT_LIGHT) {
if (aveval < thresh) /* skip sufficiently dark pixels */
continue;
nrval = (l_int32)(rval * aveval * factor);
ngval = (l_int32)(gval * aveval * factor);
nbval = (l_int32)(bval * aveval * factor);
}
else { /* type == L_PAINT_DARK */
if (aveval > thresh) /* skip sufficiently light pixels */
continue;
nrval = rval + (l_int32)((255. - rval) * aveval * factor);
ngval = gval + (l_int32)((255. - gval) * aveval * factor);
nbval = bval + (l_int32)((255. - bval) * aveval * factor);
}
composeRGBPixel(nrval, ngval, nbval, &val32);
*(line + j) = val32;
}
}
return 0;
}
/*------------------------------------------------------------------*
* Adjusting one or more colors to a target color *
*------------------------------------------------------------------*/
/*!
* pixSnapColor()
*
* Input: pixd (<optional>; either NULL or equal to pixs for in-place)
* pixs (colormapped or 8 bpp gray or 32 bpp rgb)
* srcval (color center to be selected for change: 0xrrggbb00)
* dstval (target color for pixels: 0xrrggbb00)
* diff (max absolute difference, applied to all components)
* Return: pixd (with all pixels within diff of pixval set to pixval),
* or pixs on error
*
* Notes:
* (1) For inplace operation, call it this way:
* pixSnapColor(pixs, pixs, ... )
* (2) For generating a new pixd:
* pixd = pixSnapColor(NULL, pixs, ...)
* (3) If pixs has a colormap, it is handled by pixSnapColorCmap().
* (4) All pixels within 'diff' of 'srcval', componentwise,
* will be changed to 'dstval'.
*/
PIX *
pixSnapColor(PIX *pixd,
PIX *pixs,
l_uint32 srcval,
l_uint32 dstval,
l_int32 diff)
{
l_int32 val, sval, dval;
l_int32 rval, gval, bval, rsval, gsval, bsval;
l_int32 i, j, w, h, d, wpl;
l_uint32 pixel;
l_uint32 *line, *data;
PROCNAME("pixSnapColor");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, pixd);
if (pixd && (pixd != pixs))
return (PIX *)ERROR_PTR("pixd not null or == pixs", procName, pixd);
if (pixGetColormap(pixs))
return pixSnapColorCmap(pixd, pixs, srcval, dstval, diff);
/* pixs does not have a colormap; it must be 8 bpp gray or
* 32 bpp rgb. */
if (pixGetDepth(pixs) < 8)
return (PIX *)ERROR_PTR("pixs is < 8 bpp", procName, pixd);
/* Do the work on pixd */
if (!pixd)
pixd = pixCopy(NULL, pixs);
pixGetDimensions(pixd, &w, &h, &d);
data = pixGetData(pixd);
wpl = pixGetWpl(pixd);
if (d == 8) {
sval = srcval & 0xff;
dval = dstval & 0xff;
for (i = 0; i < h; i++) {
line = data + i * wpl;
for (j = 0; j < w; j++) {
val = GET_DATA_BYTE(line, j);
if (L_ABS(val - sval) <= diff)
SET_DATA_BYTE(line, j, dval);
}
}
}
else { /* d == 32 */
extractRGBValues(srcval, &rsval, &gsval, &bsval);
for (i = 0; i < h; i++) {
line = data + i * wpl;
for (j = 0; j < w; j++) {
pixel = *(line + j);
extractRGBValues(pixel, &rval, &gval, &bval);
if ((L_ABS(rval - rsval) <= diff) &&
(L_ABS(gval - gsval) <= diff) &&
(L_ABS(bval - bsval) <= diff))
*(line + j) = dstval; /* replace */
}
}
}
return pixd;
}
/*!
* pixSnapColorCmap()
*
* Input: pixd (<optional>; either NULL or equal to pixs for in-place)
* pixs (colormapped)
* srcval (color center to be selected for change: 0xrrggbb00)
* dstval (target color for pixels: 0xrrggbb00)
* diff (max absolute difference, applied to all components)
* Return: pixd (with all pixels within diff of srcval set to dstval),
* or pixs on error
*
* Notes:
* (1) For inplace operation, call it this way:
* pixSnapCcmap(pixs, pixs, ... )
* (2) For generating a new pixd:
* pixd = pixSnapCmap(NULL, pixs, ...)
* (3) pixs must have a colormap.
* (4) All colors within 'diff' of 'srcval', componentwise,
* will be changed to 'dstval'.
*/
PIX *
pixSnapColorCmap(PIX *pixd,
PIX *pixs,
l_uint32 srcval,
l_uint32 dstval,
l_int32 diff)
{
l_int32 i, w, h, ncolors, index, found;
l_int32 rval, gval, bval, rsval, gsval, bsval, rdval, gdval, bdval;
PIX *pixm, *pixt;
PIXCMAP *cmap;
PROCNAME("pixSnapColorCmap");
if (!pixs)
return (PIX *)ERROR_PTR("pixs not defined", procName, pixd);
if (!pixGetColormap(pixs))
return (PIX *)ERROR_PTR("cmap not found", procName, pixd);
if (pixd && (pixd != pixs))
return (PIX *)ERROR_PTR("pixd not null or == pixs", procName, pixd);
if (!pixd)
pixd = pixCopy(NULL, pixs);
/* If no free colors, look for one close to the target
* that can be commandeered. */
cmap = pixGetColormap(pixd);
ncolors = pixcmapGetCount(cmap);
extractRGBValues(srcval, &rsval, &gsval, &bsval);
extractRGBValues(dstval, &rdval, &gdval, &bdval);
found = FALSE;
if (pixcmapGetFreeCount(cmap) == 0) {
for (i = 0; i < ncolors; i++) {
pixcmapGetColor(cmap, i, &rval, &gval, &bval);
if ((L_ABS(rval - rsval) <= diff) &&
(L_ABS(gval - gsval) <= diff) &&
(L_ABS(bval - bsval) <= diff)) {
index = i;
pixcmapResetColor(cmap, index, rdval, gdval, bdval);
found = TRUE;
break;
}
}
}
else { /* just add the new color */
pixcmapAddColor(cmap, rdval, gdval, bdval);
index = ncolors; /* index of new destination color */
found = TRUE;
}
if (!found) {
L_INFO("nothing to do", procName);
return pixd;
}
/* For each color in cmap that is close enough to srcval,
* add that pixel to a binary mask. */
w = pixGetWidth(pixd);
h = pixGetHeight(pixd);
pixm = pixCreate(w, h, 1);
for (i = 0; i < ncolors; i++) {
pixcmapGetColor(cmap, i, &rval, &gval, &bval);
if ((L_ABS(rval - rsval) <= diff) &&
(L_ABS(gval - gsval) <= diff) &&
(L_ABS(bval - bsval) <= diff)) {
pixt = pixGenerateMaskByValue(pixd, i);
pixOr(pixm, pixm, pixt);
pixDestroy(&pixt);
}
}
/* Use the binary mask to set all selected pixels to
* the dest color index. */
pixSetMasked(pixd, pixm, index);
pixDestroy(&pixm);
/* Remove all unused colors from the colormap. */
pixRemoveUnusedColors(pixd);
return pixd;
}
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