I don’t think there is anything built in to PIL that can do this. But I’ve modified your code so it will do it. It gets the border colour from the top left pixel, using getpixel, so you don’t need to pass the colour. Subtracts a scalar from the differenced image, this is a quick … Read more
Use the -coalesce option: convert -coalesce brocoli.gif out%05d.pgm
You need to install Ghostscript in order to rasterize vector files (PDF, EPS, PS, etc.) with ImageMagick. IM will shell out to Ghostscript when doing these manipulations (you can see it if you use the -verbose tag in your IM invocation). You could also use Ghostscript by itself to rasterize vector files.
Use this instead: convert \ input.png \ -background none \ -gravity center \ -extent 100×100 \ output.png Note well: The order of the parameters is significant! (To convince yourself, just put -background none at the end of the parameters instead of the start…) Updated: Thanks to @jesmith who noticed that the commandline I originally provided … Read more
I was getting the same error and it got resolved after installing the libmagick9-dev library on ubuntu 11. Update (Thanks to the commenters – Dec. 2012) $ sudo apt-get install libmagickwand-dev or $ sudo apt-get install graphicsmagick-libmagick-dev-compat for ubuntu 12 $ sudo apt-get install libmagickwand-dev or $ sudo apt-get install libmagick9-dev for ubuntu 11 or … Read more
It appears it’s a problem reported on the Homebrew github repo (https://github.com/mxcl/homebrew/issues/16625) blaming rmagick itself not supporting newer versions of imagemagick. On that same issue (https://github.com/mxcl/homebrew/issues/16625#issuecomment-11519383), you can find this link: https://coderwall.com/p/wnomjg which actually worked for me. This is what he does: cd /usr/local/Cellar/imagemagick/6.8.0-10/lib ln -s libMagick++-Q16.7.dylib libMagick++.dylib ln -s libMagickCore-Q16.7.dylib libMagickCore.dylib ln -s libMagickWand-Q16.7.dylib … Read more
It’s complicated because iOS 11 is actually storing tiles of HEVC encoded images in a HEIF container, but there’s a demo using the nokia lib to extract them all, ffmpeg to decode them and then stitching them into a single jpeg with imagemagick in the heiftest repo linked from corrupted HEIC tile when converting to … Read more
emcconville is correct. More specifically edit the Imagemagick policy.xml file to uncomment this line: <!– <policy domain=”module” rights=”none” pattern=”{PS,PDF,XPS}” /> –> And change it from rights=”none” to rights=”read|write” <policy domain=”module” rights=”read|write” pattern=”{PS,PDF,XPS}” /> This was a recent addition to the policy.xml file, I believe, due to a security flaw found in the Ghostscript delegate. I … Read more
I used -extent to do this: convert input.jpg -gravity center -background white -extent 50×50 output.jpg
I had this error when rendering an image using DragonFly in Rails. This happened after I upgraded to Lion (ImageMagick was installed using Brew). I reinstalled ImageMagick, jpeg, libtiff and jasper (reinstalling ImageMagick wasn’t enough by itself). brew uninstall imagemagick jpeg libtiff jasper brew install imagemagick Prior to that, running identify -list format and jpeg … Read more