[gil] Reading TGA images with origin in upper left-hand corner.

[anonymous]

Hi,

I know the TGA support is work in progress, but...

I have some TGA files that have bit 5 set in the "Image Descriptor". This causes reader_backend::read_header to throw:

"Unsupported descriptor for targa file"

The quick-n-dirty fix is just to mask out bit 5 in the check and update reader::apply such that read_data operates on a flipped_up_down_view if the bit is set.

Unfortunately I don't have any sample images that I can attach (legal reasons), but when I do I will.

Anyway hope the above is of some use.

[anonymous]

Illustration of changes (quick-n-dirty patch)

[anonymous]

Sample image file

[anonymous]

I am not an expert on image formats!

I think you are strictly adhering to the Truevision format. And I think that relaxing that requirement may have consequences w.r.t. run length encoding. It's more complicated than I first thought. None-the-less I would be grateful if you could give this issue your consideration.

[anonymous]

I used GIMP2 to generate all four combinations of:

• RLE compressed/uncompressed and
• Origin bottom left/top left

With the above patch applied read_image loaded them okay and they saved (as PNG) the right way up.

[Mateusz Loskot]

This should be fixed as part of

​https://github.com/boostorg/gil/issues/33 ​https://github.com/boostorg/gil/pull/42

If it is not working, please reopen new issue on GitHub