According to IrfanView, they are both RGB images with 1232 colors.

pngcheck -v 130228762099.png

File: 130228762099.png (135804 bytes)
chunk IHDR at offset 0x0000c, length 13
50 x 50 image, 24-bit RGB, non-interlaced
chunk sBIT at offset 0x00025, length 3
red = 8 = 0x08, green = 8 = 0x08, blue = 8 = 0x08
chunk pHYs at offset 0x00034, length 9: 2834x2834 pixels/meter (72 dpi)
chunk tEXt at offset 0x00049, length 31, keyword: Software
chunk tEXt at offset 0x00074, length 22, keyword: Creation Time
chunk prVW at offset 0x00096, length 4326
Macromedia Fireworks preview chunk (private, ancillary, unsafe to copy)
chunk mkBF at offset 0x01188, length 72
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkTS at offset 0x011dc, length 8179
Macromedia Fireworks(?) private, ancillary, unsafe-to-copy chunk
chunk mkBS at offset 0x031db, length 188
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x032a3, length 2741
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x03d64, length 1486
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x0433e, length 30461
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x0ba47, length 18861
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x10400, length 29922
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x178ee, length 508
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x17af6, length 3799
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x189d9, length 1145
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x18e5e, length 339
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x18fbd, length 4466
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x1a13b, length 311
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk mkBT at offset 0x1a27e, length 23946
Macromedia Fireworks private, ancillary, unsafe-to-copy chunk
chunk IDAT at offset 0x20014, length 4692
zlib: deflated, 8K window, maximum compression
chunk IEND at offset 0x21274, length 0
No errors detected in 130228762099.png (23 chunks, -1710.7% compression).

Apparently Fireworks stores extra data about the picture in mkBT chunks which is perfectly valid but very sloppy on the part of the image's creator. This extra information should have be stripped before sending the image out to the internet.

>>97
Interesting. I looked up that program and it comes with another utility for breaking apart the different chunks and numbering them. so now I've got a batch script to delete the ancillary chunks and reassemble the remaining ones in order (currently it only works with a single IDAT chunk). The only thing is I'd like it to use a variable for the output file based on the the beginning of input filename. Not quite sure how to do that.

Mods can move this to [code/ now, probably more relevant there...

who knows

nevermind, I found a program called TweakPNG that lets you selectively edit and delete chunks inside the png file. defl0pt also removes all ancillary chunks in a quick pass.