ImageMagick no decode delegate

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

ImageMagick: scale JPEG image with a maximum file-size

To restrict the resulting image to a maximum file size, you can use the commandline parameter -define jpeg:extent=max_value, like this: convert original.jpeg -define jpeg:extent=300kb output.jpg convert original.jpeg -define jpeg:extent=300kb -scale 50% output.jpg convert original.jpeg -define jpeg:extent=300kb […other options…] output.jpg Note, this will not always work to match the exact size you wanted. You may have … Read more

convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

Note: the solution in this and other answers involves disabling safety measures that are there to fix arbitrary code execution vulnerabilities. See for instance this ghostscript-related and this ubuntu-related announcement. Only go forward with these solutions if the input to convert comes from a trusted source. I use ImageMagick in php (v.7.1) to slice PDF … Read more