Legacy ImageMagick Discussions Archive

thanks, this is the solution like several times before, IM changed the processing of (undefined RAW) RGB/sRGB in pipes from 6.8.8 to 6.8.9 the image is RGB $ identify t1.png t1.png PNG 320x240 320x240+0+0 16-bit RGB 52.7KB 0.000u 0:00.000 and this works fine $ convert t1.png -set colorspace sRGB ...

I think, the cause is a new handling of embedded gamma values http://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/?action=dlattach;attach=71019;image image t1.png from above has a unusual gamma of 1 >identify -format %[gamma] t1.png 1 after converting the png to a text file ...

it's a gamma problem same sample image t1.png as above http://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/?action=dlattach;attach=71019;image old IM 6.8.8 >C:\util\ImageMagick-6.8.8-Q16\convert.exe t1.png gray:- | hexdump | head 00000000: 2F 87 2F 88 2F 88 2F 87 - 2F 89 2F ...

see the difference >C:\util\ImageMagick-6.8.8-Q16\convert.exe t1.png gray:- | hexdump 00000000: 2F 87 2F 88 2F 88 2F 87 - 2F 89 2F 8C 2F 8A 2F 8E |/ / / / / / / / | 00000010: 2F 8E 2F 8D 2F 8D 2F 8C - 2F 8B 2F 8B 2F 8A 2F 8A |/ / / / / / / / | 00000020: 2F 8A 2F 89 2F 89 2F 88 - 2F 87 2F 86 2F 85 2F ...

great hint, in Linux/Mac I only use "hexdump -C" but I'm sitting here with a x64 windows 8 pc and a GnuWin32 hexdump.exe (without parameter C) the same with full paths >C:\util\GnuWin32\bin\echo.exe -n ABCDED | C:\util\GnuWin32\bin\hexdump 00000000: 41 42 43 44 45 44 - |ABCDED| 00000006; >C:\util ...

edit: subject changed to "png and gamma value" ---------------- here we discussed about PNG images with wrong byte order http://www.imagemagick.org/discourse-server/viewtopic.php?f=2&t=24818 http://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/?action=dlattach;attach=71019 ...

the next release: there is unfortunately furthermore no Q16 imagemagick download avaible for Windows x86 (I use a 32 Bit Windows VM) neither static nor dynamic ;-( the new package imagemagick.org/download/binaries/ImageMagick-6.8.8- 6 -Q16-x86-windows.zip contains the "old" verson 6.8.8- 5 http ...

only a minor bug: go to http://www.imagemagick.org/script/binary-releases.php ImageMagick-6.8.8-5- Q16 -x86-windows.zip Portable Win32 static at 16 bits-per-pixel . Just copy to your host and run (no installer, no Windows registry entries). after extracting the ImageMagick-6.8.8-5- Q16 -x86-windows ...

I found the new switch in the current public version of IM 6 SVN revision 14676 (2014-01-29 6.8.8-4) but I can't find the right syntax first check binary IM_MOD_RL_png_.dll for the new option png:swap-bytes : > strings.exe ImageMagick-6.8.8-Q16\modules\coders\IM_MOD_RL_png_.dll | grep swap png:swap ...

glennrp wrote:Checked in to IM6 SVN revision 14464 a new "-define png:swap-bytes" option.

a perfect solution for this problem
thanks

its a job for a new PNGTool

Thanks for help!!

ups, you are right but ImageMagick think for me $ echo -n ABCDEF | convert -size "3X1" -depth 16 gray:- \( -clone 0 -evaluate RightShift 8 \) \( -clone 0 -evaluate And 255 -evaluate LeftShift 8 \) -delete 0 -compose Plus -composite - | hexdump -C 00000000 42 41 44 43 46 45 |BADCFE| $ echo -n ABCDEF ...

@snibgo a great solution, 11x faster as my fx operator hack $ time convert 1.png -fx 'u/256+int(u*65536)%256)/256' out1.png real 0m0.876s $ time convert 1.png \( -clone 0 -evaluate RightShift 8 \) \( -clone 0 -evaluate And 255 -evaluate LeftShift 8 \) -delete 0 -compose Plus -composite out.png real ...

Of course one could edit the file in something like EXIFTool before processing it in IM. I asked Phil (the coder of exiftool) this question a year ago and he wrote http://u88.n24.queensu.ca/exiftool/forum/index.php/topic,4898.msg23672.html#msg23672 I just return the PNG as is ...(ExifTool doesn't ...

some Flir thermal cameras save the images a 16 Bit PNG with a wrong byte order ( for further infos see this post http://www.eevblog.com/forum/testgear/flir-e4-thermal-imaging-camera-teardown/msg348398/#msg348398 ) here is a 16 Bit sample PNG with a wrong byte order http://www.eevblog.com/forum ...