[cairo] BUG: CAIRO_FORMAT_ARGB32, image_surface transparency = CAIRO_IMAGE_IS_OPAQUE after write_png()

Tue Jun 7 21:46:07 UTC 2016

On Tue, 7 Jun 2016 21:17:01 +0930, Adrian Johnson wrote:

> It is helpful when writing out PNG images for debugging purposes to
> know if an ARGB32 image is opaque.

A command like “identify -verbose” can already show you that, can it
not?

> It also reduces the size of the 2978 out of 3458 reference images in
> cairo test suite that are opaque.

PNG is not exactly designed for compactness.