[cairo] trouble with existing PNG in CAIRO_FORMAT_A8

[Tristen Ennemuist]

hello!

i'm having a spot of trouble with grayscale png images.

i can load png images using cairo_image_surface_create_from_png, but subsequent calls to cairo_image_surface_get_format never return CAIRO_FORMAT_A8, even when the original png format is actually CAIRO_FORMAT_A8. it seems to always automatically convert to CAIRO_FORMAT_RGB24, leaving me no way of knowing the original file format - that is as far as i can tell...

i don't really mind this automatic conversion behaviour (as i can extract the data from the surface any way i like), but, if i'm not mistaken, what's causing me the real trouble is not being able to detect if the image was originally grayscale or rgb.

is there some way i can go about detecting the original png file format?


(i tried using gdk_pixbuf_new_from_file and found that also automatically converts.)


regards and thanks!

tristen
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