Scale to a percentage of the original size ImageMagick techniquesĬonvert all the images created by AVS/Express image_capture module to PNGĬonvert an image created by AVS/Express image_capture module to PNG removingĪll strange settings that could impact later movie production using mencoder convert AVS:Img00001.x +matte +page -depth 8 -type TrueColor Img00001.pngįlip an image produced using wrong setting of the flip switch in AVS/Express MinGW and run them under sh from a command window. Otherwise when you launch convert, the windows convert filesystem command will be called.įor scripts that should work on windows and Linux I suggest installing Cygwin or On Windows be careful with the definition of the PATH variable: ImageMagick install directory should come first, ImageMagick is available by default on Linux and can be installed and used on Windows. They have been tried and found useful for some needs. Here I collect some usefulĬommand lines I used for visualization images post processing.Ī more general collection of ImageMagick useful tricks can be found on the excellentĪt the end a quick coverage of other image manipulation tools. Tested in Ubuntu 18.10, ffpmeg 4.0.2-2, ImageMagick 6.9.10-8.Mario Valle Web > Post processing & visual communication Image toolsĪfter producing beautiful images, sometimes some form of image postprocessing is needed. TODO: why can they make it smaller than convert? Are they just selecting better more minimal diff rectangles, or something else? See also: How do I create an animated gif from still images (preferably with the command line)? Gifsicle -resize 256x256 out-convert.gif > out-gifsicle.gifĪnd both produced an even smaller correctly looking 1.5 MiB output. I also tried out the following commands: ffmpeg -i out-convert.gif -vf scale=256:-1 out-ffmpeg-small.gif Not considerably smaller than out-coalesce.gif, but I think this is just because the black ground compresses really well, and it could be very significant in general. Out-deconstruct.gif: compressed frames, final output size 1.9 MiB. Output looks visually correct, but the output file size is 2.0 MiB, which is larger than out-deconstruct.gif Out-coalesce.gif: all frames are 256x256 and have the correct offset 0+0. Visually incorrect, since those approximately 256x256 frames have a non-zero offset, e.g. Out.gif: All frames are 256x256 or larger, and huge at about 5MiB, TODO why? Then, if we compare the three conversions: $ identify out-deconstruct.gif | head -n 3 $ convert out-convert.gif -coalesce -resize 256x -deconstruct out-deconstruct.gif $ convert out-convert.gif -coalesce -resize 256x out-coalesce.gif $ convert out-convert.gif -resize 256x out.gif Using the test data from this answer: How do I create an animated gif from still images (preferably with the command line)? we can see this clearly with identify: $ identify out-convert.gif | head -n 3 coalesce then expands all the frames to the original size, which makes the resize work, but it does not re-compress the frames again as your input image: -deconstruct is needed for that! The root cause of the problem is that your input GIF was properly minimized: GIF allows the next frame to be just the modified rectangle from the previous one at an offset. After -coalesce, you likely want to add a -deconstruct: convert in.gif -coalesce -resize 256x -deconstruct out-deconstruct.gif
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