pngtopnm: reading a 640w x 300h image, 8 bits
pngtopnm: truecolor+alpha, not interlaced, base filter
pngtopnm: background {index, gray, red, green, blue} = {0, 0, 0, 0, 0}
pngtopnm: tRNS chunk (transparency): not present
pngtopnm: gAMA chunk (image gamma): not present
pngtopnm: sBIT chunk: not present
pngtopnm: cHRM chunk: not present
pngtopnm: PLTE chunk: not present
pngtopnm: bKGD chunk: present
pngtopnm: hIST chunk: not present
pngtopnm: pHYs chunk: present
pngtopnm: oFFs chunk: not present
pngtopnm: tIME chunk: not present
pngtopnm: pCAL chunk: not present
pngtopnm: sRGB chunk: not present
pngtopnm: writing a PPM file (maxval=255)
pnmremap: 16 colors found in colormap
pnmremap: 0 pixels not matched in color map
192000 pixels, 88267 bytes, (8.06% compression)
#081428=0
#081c35=1
#10203d=2
#142441=3
#0c2449=4
#0c2d55=5
#14284d=6
#ffffff=7
#14315d=8
#283545=9
#204d8e=10
#4d5969=11
#8e9aa6=12
#82b2ff=13
#c2caca=14
#e7f3ff=15
pnmtopng: reading a PPM file (maxval=255)
pnmtopng: Finding colors in input image...
pnmtopng: 16 colors found
pnmtopng: reading ordered palette (colormap)...
pnmtopng: 16 colors found
pnmtopng: PNG palette has 16 entries, 0 of them non-opaque
pnmtopng: Writing 4-bit color indexes
pnmtopng: writing a 4-bit palette file