simple PNGs with one transparent color are just slightly off from perfectly transparent. i only noticed it when layering several PNGs so that the effect was cumulative, but later testing showed a single PNG was causing a slight alpha even with its full transparent pixels in the test case, the background color of #888888 is being alpha'd to #878787 by a single PNG on the left and 12 of the same PNGs push it #7c8787 on the right. the PNG was created by GD (PHP bindings) like so: $im=imageCreate(255,227); $trcolor=imageColorAllocate($im,0,0,0); imageColorTransparent($im,$trcolor); $color=imageColorAllocate($im,0xcc,0,0); imageFilledRectangle($im,0,0,255,227,$trcolor); imageFilledPolygon($im,$coords,count($coords)/2,$color); imagePNG($im,"a_1.png"); i dont know enough to determine if GD's PNG encoding is at fault but it seems unlikely for something so simple. even IE's **** PNG renderer does this correctly.
Confirming 10/25 cvs on Win2k. I can't find a dupe for this and the testcase is noticeably different on IE6.
Status: UNCONFIRMED → NEW
Ever confirmed: true
This happens on Linux as well (2002-10-25-08 trunk build).
Severity: minor → normal
OS: Windows XP → All
Hardware: PC → All
The background of that PNG is (0,135,135) with an alpha value of 1.
Status: NEW → RESOLVED
Last Resolved: 16 years ago
Resolution: --- → INVALID
error *was* in GD
Status: RESOLVED → CLOSED
You need to log in before you can comment on or make changes to this bug.