[GH-ISSUE #439] How to insert image data of type CV:: Mat #343

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opened 2026-05-05 12:10:46 -06:00 by gitea-mirror · 2 comments

gitea-mirror commented

2026-05-05 12:10:46 -06:00

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Originally created by @ZRBzrb6119 on GitHub (Apr 18, 2024).
Original GitHub issue: https://github.com/jmcnamara/libxlsxwriter/issues/439

Originally assigned to: @jmcnamara on GitHub.

The byte data of type CV:: Mat seems to fail the image type verification
if (memcmp(&signature[1], "PNG", 3) == 0) { if (_process_png(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (signature[0] == 0xFF && signature[1] == 0xD8) { if (_process_jpeg(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (memcmp(signature, "BM", 2) == 0) { if (_process_bmp(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (memcmp(signature, "GIF8", 4) == 0) { if (_process_gif(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else { LXW_WARN_FORMAT1("worksheet image insertion: " "unsupported image format for: %s.", image_props->filename); return LXW_ERROR_IMAGE_DIMENSIONS; }

Originally created by @ZRBzrb6119 on GitHub (Apr 18, 2024). Original GitHub issue: https://github.com/jmcnamara/libxlsxwriter/issues/439 Originally assigned to: @jmcnamara on GitHub. The byte data of type CV:: Mat seems to fail the image type verification ` if (memcmp(&signature[1], "PNG", 3) == 0) { if (_process_png(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (signature[0] == 0xFF && signature[1] == 0xD8) { if (_process_jpeg(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (memcmp(signature, "BM", 2) == 0) { if (_process_bmp(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else if (memcmp(signature, "GIF8", 4) == 0) { if (_process_gif(image_props) != LXW_NO_ERROR) return LXW_ERROR_IMAGE_DIMENSIONS; } else { LXW_WARN_FORMAT1("worksheet image insertion: " "unsupported image format for: %s.", image_props->filename); return LXW_ERROR_IMAGE_DIMENSIONS; } `

gitea-mirror

2026-05-05 12:10:47 -06:00

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gitea-mirror commented

2026-05-05 12:10:52 -06:00

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@jmcnamara commented on GitHub (Apr 18, 2024):

Some questions:

Is the image type in the buffer actually supported by libxlsxwriter/Excel?
If so what happens if you dump the image to a file and then create a simple hello world program that inserts the image from the file (not buffer)?
Could you attach a sample image that is failing?

@jmcnamara commented on GitHub (Apr 18, 2024): Some questions: - Is the image type in the buffer actually supported by libxlsxwriter/Excel? - If so what happens if you dump the image to a file and then create a simple hello world program that inserts the image from the file (not buffer)? - Could you attach a sample image that is failing?

gitea-mirror commented

2026-05-05 12:10:54 -06:00

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@jmcnamara commented on GitHub (Apr 28, 2024):

Closing due to lack of feedback. I will reopen with a working example or if the questions above are answered.

@jmcnamara commented on GitHub (Apr 28, 2024): Closing due to lack of feedback. I will reopen with a working example or if the questions above are answered.

gitea-mirror referenced this issue

2026-05-05 12:16:39 -06:00

[PR #343] [CLOSED] Theoretical Fix issue with BoringSSL-GRPC via update to the podspec #465