Posterize acting different in PerlMagick vs command line
Posted: 2018-07-07T08:21:47-07:00
Linux Version: ImageMagick 6.7.8-9 2016-06-16 Q16 on CentOS 7
Windows Version: ImageMagick 7.0.8-5 Q16 x64 on Windows 10
I'm using PerlMagick and I need to reduce images down to the following basic colors:
0x000000 (black)
0x0000FF (blue)
0x00FF00 (green)
0x00FFFF (cyan, or html aqua)
0xFF0000 (red)
0xFF00FF (magenta, or html fuchsia)
0xFFFF00 (yellow)
0xFFFFFF (white)
I've been playing with posterize but I can't quite figure out how to make sure that those are the only colors in the output.
It works great in Win10 with the following command:
Yet when I run the following in PerlMagick on CentOS I only get the desired result in MOST files:
The result image has colors that are definitely not in that pallet.
I'm starting to think it's down to PerlMagick's implementation, or the differences between Windows and Linux versions. Any suggestions?
Windows Version: ImageMagick 7.0.8-5 Q16 x64 on Windows 10
I'm using PerlMagick and I need to reduce images down to the following basic colors:
0x000000 (black)
0x0000FF (blue)
0x00FF00 (green)
0x00FFFF (cyan, or html aqua)
0xFF0000 (red)
0xFF00FF (magenta, or html fuchsia)
0xFFFF00 (yellow)
0xFFFFFF (white)
I've been playing with posterize but I can't quite figure out how to make sure that those are the only colors in the output.
It works great in Win10 with the following command:
Code: Select all
magick input.png -posterize 2 output.pngCode: Select all
$image->Read("input.png");
$image->Posterize(levels => 2, dither => 'false'); # dither doesn't make a difference either way
$image->write('output.png');Code: Select all
160392: ( 0, 0, 0,255) #000000FF black
8: ( 0, 0, 0,213) #000000D5 srgba(0,0,0,0.835294)
7: ( 0, 0, 0,230) #000000E6 srgba(0,0,0,0.901961)
6: ( 0, 0, 0,250) #000000FA srgba(0,0,0,0.980392)
3: ( 0, 0, 0,244) #000000F4 srgba(0,0,0,0.956863)
1013: ( 0,255,255,255) #00FFFFFF cyan
570: (125, 25,130,255) #7D1982FF srgba(125,25,130,1)
88001: (255,255,255,255) #FFFFFFFF white