Minecraft 1.5.1, Snapshot 13w19a, Snapshot 13w21a, Minecraft 1.6, Minecraft 1.6.1, Minecraft 1.6.2, Minecraft 13w36a, Minecraft 13w36b, Minecraft 1.7.2, Minecraft 13w48b, Minecraft 1.7.4, Minecraft 14w08a, Minecraft 14w29b, Minecraft 1.8, Minecraft 1.8.3, Minecraft 1.8.8, Minecraft 15w42a, Minecraft 1.9, Minecraft 1.10
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_01, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
OpenGL: GeForce 9200/integrated/SSE2 GL version 3.3.0, NVIDIA Corporation
Is Modded: No.
Minecraft does not process some PNGs correctly. Specifically, it does not seem to implement the tRNS specification fully, nor does it handle greyscale PNGs correctly. Attached are some vanilla textures from the most recent snapshot as of this writing (15w42a) that render incorrectly when compressed with ScriptPNG's most aggressive lossless setting. (If Mojang did this compression themselves, Minecraft's PNGs would be 34.45% [1299 KB] smaller, which is a not-insignificant amount of bandwidth.)