PNG transparency test

Examples from http://entropymine.com/jason/testbed/pngtrans/

Not all possible results are shown; there are too many combinations of background colors and shapes of the opaque region. However, I intend to include every result that actually occurs in a mainstream browser. If I am missing any, please let me know.

It's come to my attention that my images which show how alpha transparency should look are not quite perfect in regard to precisely how transparent they are at various points. Rather than try to modify this page to test gamma correction issues as well, I've created a separate test page for that.

This test page was constructed by Jason Summers. Comments may be emailed to jason1@pobox.com.
There are other test pages listed at the PNG web site.

Alpha and palette transparency

Expected result:
[Test image]

(T1) 8-bit palette, includes background color:
[Test image]

(T2) 8-bit palette, no background color:
[Test image]

(T3) 32-bit RGBA, includes background color:
[Test image]

(T4) 32-bit RGBA, no background color:
[Test image]

(T5) 64-bit RGBA, includes background color:
[Test image]

(T6) 64-bit RGBA, no background color:
[Test image]

RGB binary transparency

Expected result:
[Test image]

(T7) 24-bit RGB, binary transparency, includes background color:
[Test image]

(T8) 24-bit RGB, binary transparency, no background color:
[Test image]

(T9) 48-bit RGB, binary transparency, includes background color:
[Test image]

(T10) 48-bit RGB, binary transparency, no background color:
[Test image]

Grayscale alpha transparency

Expected result:
[Test image]

(G1) 16 bpp grayscale (8 gray + 8 alpha), includes background color:
[Test image]

(G2) 16 bpp grayscale (8 gray + 8 alpha), no background color:
[Test image]

(G3) 32 bpp grayscale (16 gray + 16 alpha), includes background color:
[Test image]

(G4) 32 bpp grayscale (16 gray + 16 alpha), no background color:
[Test image]

Grayscale binary transparency

Expected result:
[Test image]

(G5) 8 bpp grayscale (8 gray), includes background color:
[Test image]

(G6) 8 bpp grayscale (8 gray), no background color:
[Test image]

(G7) 16 bpp grayscale (16 gray), includes background color:
[Test image]

(G8) 16 bpp grayscale (16 gray), no background color:
[Test image]

Miscellaneous

(M1) 8-bit palette, no transparency, includes background color:
Expected result:
[Test image]
[Test image]

(M2) (4-bit) palette, binary transparency only, no background color:
Expected result:
[Test image]
[Test image]
(This tests a few things that may have slipped through the cracks.)