#266 FreeImage loads some 32bpp BMP files in GBAR order instead of RGBA order

[Steve Mokris]

The attached program loads 3 images with FreeImage:

• photoshop-red.bmp and gimp-red.png are consistent and have pixel values in the expected RGBA order (ff00007f)
• but gimp-red.bmp's pixels are in the wrong order: GBAR (00007fff)

Here's how I created the images:

• Launch GIMP 2.8.16
• Create a new image, 3x1 pixels, Advanced > Fill with Transparency
• Zoom in
• Select the pencil tool, Opacity 100, Pixel brush, size 1, Dynamics > Fade length 0
• Select color solid red (255,0,0)
• Click on the rightmost pixel
• Select Opacity 50
• Click on the center pixel — there should now be a 3-step alpha gradient: 0%, 50%, 100%
• File > Export As > BMP, Advanced > 32 bits > A8 R8 G8 B8, click Export — gimp-red.bmp
• File > Export As > PNG, click Export — gimp-red.png
• Open the BMP in Photoshop, and re-save it as another BMP file — photoshop-red.bmp

[Mihail Naydenov]

The attached gimp-red.bmp is not PNG compressed, according to its header, but BITFIELDS.
At the moment FreeImage aborts loading, as only jpeng and png compressed BMPs are supported.