I need to join 2 PNG images, with 16 color palette, keep colors number and order as originals.
Both PNGs use the same 16 color palette.
There is a way to create 4 bit indexed PNG with all colors, in exact order, even unused in each PNG?
Edit to be more clear:
I have 2 pictures. The first is "level-000.png":
It is identified as:
Image: level-000.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: PseudoClass
Geometry: 144x144+0+0
Resolution: 28.35x28.35
Print size: 5.07937x5.07937
Units: PixelsPerCentimeter
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 20736
Red:
min: 0 (0)
max: 184 (0.721569)
mean: 88.6151 (0.34751)
standard deviation: 27.9329 (0.109541)
kurtosis: 1.7675
skewness: 0.143857
Green:
min: 0 (0)
max: 199 (0.780392)
mean: 68.8957 (0.270179)
standard deviation: 22.7411 (0.0891808)
kurtosis: 18.2722
skewness: 2.87959
Blue:
min: 0 (0)
max: 111 (0.435294)
mean: 19.4671 (0.0763416)
standard deviation: 22.1775 (0.0869706)
kurtosis: 2.80475
skewness: 1.17593
Image statistics:
Overall:
min: 0 (0)
max: 199 (0.780392)
mean: 58.9926 (0.231344)
standard deviation: 24.4216 (0.095771)
kurtosis: 17.5446
skewness: 0.948025
Colors: 4
Histogram:
390: ( 0, 0, 0) #000000 black
10196: ( 67, 57, 0) #433900 srgb(67,57,0)
9770: (111, 79, 37) #6F4F25 srgb(111,79,37)
380: (184,199,111) #B8C76F srgb(184,199,111)
Colormap entries: 16
Colormap:
0: ( 0, 0, 0) #000000 black
1: (255,255,255) #FFFFFF white
2: (104, 55, 43) #68372B srgb(104,55,43)
3: (112,164,178) #70A4B2 srgb(112,164,178)
4: (111, 61,134) #6F3D86 srgb(111,61,134)
5: ( 88,141, 67) #588D43 srgb(88,141,67)
6: ( 53, 40,121) #352879 srgb(53,40,121)
7: (184,199,111) #B8C76F srgb(184,199,111)
8: (111, 79, 37) #6F4F25 srgb(111,79,37)
9: ( 67, 57, 0) #433900 srgb(67,57,0)
10: (154,103, 89) #9A6759 srgb(154,103,89)
11: ( 68, 68, 68) #444444 srgb(68,68,68)
12: (108,108,108) #6C6C6C srgb(108,108,108)
13: (154,210,132) #9AD284 srgb(154,210,132)
14: (108, 94,181) #6C5EB5 srgb(108,94,181)
15: (149,149,149) #959595 srgb(149,149,149)
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: black
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 144x144+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2015-04-10T12:24:18+02:00
date:modify: 2015-04-09T22:33:29+02:00
png:bKGD: chunk was found (see Background color, above)
png:IHDR.bit-depth-orig: 4
png:IHDR.bit_depth: 4
png:IHDR.color-type-orig: 3
png:IHDR.color_type: 3 (Indexed)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 144, 144
png:pHYs: x_res=2835, y_res=2835, units=1
png:PLTE.number_colors: 16
png:sRGB: intent=0 (Perceptual Intent)
signature: 00d9489d55480d588c3329ab0fa844ed2a67eea06fd4dfa793503a36f9c4b160
Artifacts:
filename: level-000.png
verbose: true
Tainted: False
Filesize: 337B
Number pixels: 20.7K
Pixels per second: 0B
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.8.9-8 Q16 x86_64 2014-11-18
The second pic is "scacchiera.png".
It is identified as:
Image: scacchiera.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: PseudoClass
Geometry: 144x144+0+0
Resolution: 28.35x28.35
Print size: 5.07937x5.07937
Units: PixelsPerCentimeter
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 20736
Red:
min: 67 (0.262745)
max: 111 (0.435294)
mean: 89 (0.34902)
standard deviation: 22 (0.0862745)
kurtosis: -2
skewness: -1.18433e-11
Green:
min: 57 (0.223529)
max: 79 (0.309804)
mean: 68 (0.266667)
standard deviation: 11 (0.0431373)
kurtosis: -2
skewness: 7.03683e-11
Blue:
min: 0 (0)
max: 37 (0.145098)
mean: 18.5 (0.072549)
standard deviation: 18.5 (0.072549)
kurtosis: -2
skewness: 0
Image statistics:
Overall:
min: 0 (0)
max: 111 (0.435294)
mean: 58.5 (0.229412)
standard deviation: 17.7694 (0.0696837)
kurtosis: 29.9398
skewness: -1.66976
Colors: 2
Histogram:
10368: ( 67, 57, 0) #433900 srgb(67,57,0)
10368: (111, 79, 37) #6F4F25 srgb(111,79,37)
Colormap entries: 16
Colormap:
0: ( 0, 0, 0) #000000 black
1: (255,255,255) #FFFFFF white
2: (104, 55, 43) #68372B srgb(104,55,43)
3: (112,164,178) #70A4B2 srgb(112,164,178)
4: (111, 61,134) #6F3D86 srgb(111,61,134)
5: ( 88,141, 67) #588D43 srgb(88,141,67)
6: ( 53, 40,121) #352879 srgb(53,40,121)
7: (184,199,111) #B8C76F srgb(184,199,111)
8: (111, 79, 37) #6F4F25 srgb(111,79,37)
9: ( 67, 57, 0) #433900 srgb(67,57,0)
10: (154,103, 89) #9A6759 srgb(154,103,89)
11: ( 68, 68, 68) #444444 srgb(68,68,68)
12: (108,108,108) #6C6C6C srgb(108,108,108)
13: (154,210,132) #9AD284 srgb(154,210,132)
14: (108, 94,181) #6C5EB5 srgb(108,94,181)
15: (149,149,149) #959595 srgb(149,149,149)
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 144x144+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2015-04-10T20:46:55+02:00
date:modify: 2015-04-10T20:46:55+02:00
png:IHDR.bit-depth-orig: 4
png:IHDR.bit_depth: 4
png:IHDR.color-type-orig: 3
png:IHDR.color_type: 3 (Indexed)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 144, 144
png:pHYs: x_res=2835, y_res=2835, units=1
png:PLTE.number_colors: 16
png:sRGB: intent=0 (Perceptual Intent)
signature: 8a0ca53e6e6f8e8fc4b141c7194b399ed1fc32473b174b6240addbb3f98864e5
Artifacts:
filename: scacchiera.png
verbose: true
Tainted: False
Filesize: 241B
Number pixels: 20.7K
Pixels per second: 0B
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.8.9-8 Q16 x86_64 2014-11-18
As you can see, both pics have same colors:
Colormap entries: 16
Colormap:
0: ( 0, 0, 0) #000000 black
1: (255,255,255) #FFFFFF white
2: (104, 55, 43) #68372B srgb(104,55,43)
3: (112,164,178) #70A4B2 srgb(112,164,178)
4: (111, 61,134) #6F3D86 srgb(111,61,134)
5: ( 88,141, 67) #588D43 srgb(88,141,67)
6: ( 53, 40,121) #352879 srgb(53,40,121)
7: (184,199,111) #B8C76F srgb(184,199,111)
8: (111, 79, 37) #6F4F25 srgb(111,79,37)
9: ( 67, 57, 0) #433900 srgb(67,57,0)
10: (154,103, 89) #9A6759 srgb(154,103,89)
11: ( 68, 68, 68) #444444 srgb(68,68,68)
12: (108,108,108) #6C6C6C srgb(108,108,108)
13: (154,210,132) #9AD284 srgb(154,210,132)
14: (108, 94,181) #6C5EB5 srgb(108,94,181)
15: (149,149,149) #959595 srgb(149,149,149)
If i join them with
convert -page 312x144+0+0 "scacchiera.png" -page +168+0 \
"level-000.png" -background black -layers flatten "joined.png"
then "joined.png" picture is:
It is identified as:
Image: joined.png
Format: PNG (Portable Network Graphics)
Mime type: image/png
Class: PseudoClass
Geometry: 312x144+0+0
Resolution: 28.35x28.35
Print size: 11.0053x5.07937
Units: PixelsPerCentimeter
Type: Palette
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 44928
Red:
min: 0 (0)
max: 184 (0.721569)
mean: 81.9762 (0.321475)
standard deviation: 33.8163 (0.132613)
kurtosis: 0.917842
skewness: -0.743586
Green:
min: 0 (0)
max: 199 (0.780392)
mean: 63.1826 (0.247775)
standard deviation: 25.0478 (0.0982265)
kurtosis: 7.85041
skewness: 0.0804364
Blue:
min: 0 (0)
max: 111 (0.435294)
mean: 17.5233 (0.0687188)
standard deviation: 20.2675 (0.0794802)
kurtosis: 1.51309
skewness: 0.876441
Image statistics:
Overall:
min: 0 (0)
max: 199 (0.780392)
mean: 54.2274 (0.212656)
standard deviation: 26.9673 (0.105754)
kurtosis: 7.87712
skewness: 0.327418
Colors: 4
Histogram:
3846: ( 0, 0, 0) #000000 black
20564: ( 67, 57, 0) #433900 srgb(67,57,0)
20138: (111, 79, 37) #6F4F25 srgb(111,79,37)
380: (184,199,111) #B8C76F srgb(184,199,111)
Colormap entries: 4
Colormap:
0: ( 67, 57, 0) #433900 srgb(67,57,0)
1: (111, 79, 37) #6F4F25 srgb(111,79,37)
2: ( 0, 0, 0) #000000 black
3: (184,199,111) #B8C76F srgb(184,199,111)
Rendering intent: Perceptual
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: black
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 312x144+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
date:create: 2015-04-12T15:13:11+02:00
date:modify: 2015-04-12T15:13:11+02:00
png:bKGD: chunk was found (see Background color, above)
png:cHRM: chunk was found (see Chromaticity, above)
png:gAMA: gamma=0.45454544 (See Gamma, above)
png:IHDR.bit-depth-orig: 2
png:IHDR.bit_depth: 2
png:IHDR.color-type-orig: 3
png:IHDR.color_type: 3 (Indexed)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height: 312, 144
png:pHYs: x_res=2835, y_res=2835, units=1
png:PLTE.number_colors: 4
png:sRGB: intent=0 (Perceptual Intent)
png:text: 2 tEXt/zTXt/iTXt chunks were found
signature: 2049a10c0a2a73f864125d0ba93ccfc604a750667e3ba1d0fe8fe3be38a1cbea
Artifacts:
filename: joined.png
verbose: true
Tainted: False
Filesize: 487B
Number pixels: 44.9K
Pixels per second: 4.493MB
User time: 0.000u
Elapsed time: 0:01.009
Version: ImageMagick 6.8.9-8 Q16 x86_64 2014-11-18
and you can see that palette is totally different from the initial one.
Images are here:
- www.dropbox.com/s/jdftk03rizeqcub/scacchiera.png
- www.dropbox.com/s/9c1fmav5qni8u2m/level-000.png
- www.dropbox.com/s/8hhd1zyzb31c4me/joined.png
The question is: is there a way to have ALWAYS this palette:
Colormap entries: 16
Colormap:
0: ( 0, 0, 0) #000000 black
1: (255,255,255) #FFFFFF white
2: (104, 55, 43) #68372B srgb(104,55,43)
3: (112,164,178) #70A4B2 srgb(112,164,178)
4: (111, 61,134) #6F3D86 srgb(111,61,134)
5: ( 88,141, 67) #588D43 srgb(88,141,67)
6: ( 53, 40,121) #352879 srgb(53,40,121)
7: (184,199,111) #B8C76F srgb(184,199,111)
8: (111, 79, 37) #6F4F25 srgb(111,79,37)
9: ( 67, 57, 0) #433900 srgb(67,57,0)
10: (154,103, 89) #9A6759 srgb(154,103,89)
11: ( 68, 68, 68) #444444 srgb(68,68,68)
12: (108,108,108) #6C6C6C srgb(108,108,108)
13: (154,210,132) #9AD284 srgb(154,210,132)
14: (108, 94,181) #6C5EB5 srgb(108,94,181)
15: (149,149,149) #959595 srgb(149,149,149)
exactly with these 16 colors and in this order for each resluting PNG?
I have tried some more and I can't see a way to do this with ImageMagick. You can extract the unique colours from
scacchiera.png
like this:but there are only 2 colours in there, so that is no use:
You can also extract the colormap and make a CLUT like this:
which gives you this
You can then use that CLUT like this, but it doesn't help
and you can also use it like this but that doesn't work either
You can also try to tell ImageMagick to preserve the colormap like this, but I'll leave you to guess whether that works :-(
So, I am stuck too :-)
Original Answer
You don't say how you want to join your images, nor provide any images, nor show what you have tried, so you may not get a good answer. This may be close though...
I have worked on this some more, and believe I can achieve what you want... basically, I allow ImageMagick to do the repaging and joining of the images exactly as you had it, but then I get ImageMagick to output a NetPBM file in Portable Any Map
PNM
format. I then encode thePNM
format file into a PNG using a Perl encoder I wrote to match your very specific needs as regards the palette. So, for every truecolour 24-bit RGB pixel I read in from thePNM
file, I compute which palette entry it is nearest to by doing the sum of the square errors, and then outputting a single palette index.NetPBM
is described here.The
PNM
format is really simple to parse and that's why I chose it. It is described here.So, your original command would be almost identical, except a
PNM
file is output onstdout
and read into the Perl scriptpnmtopng
which then makes thePNG
file you wanted:The Perl script is here:
The result is this: