How to create square/cropped thumbnail using ImageMagick ? Cropping like below.
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This is explained in the official ImageMagick documentation under, “Cut the Thumbnail to Fit”:
An alternative, is rather than pad out the image to fit the specific thumbnail size we want, is to instead cut off the parts of the image that does not fit the final size.
Of course this means you actually lose some parts of the original image, particularly the edges of the image, but the result is a enlarged thumbnail of the center part of the image. This is usually (but not always) the main subject of the image, so it is a practical method of thumbnail creation.
As of IM v6.3.8-3 the special resize option flag '^' was added to make this easier. We just resize using this flag then crop off the parts of the image that overflows the desired size.
And in the context of an example command:
convert -define jpeg:size=200x200 hatching_orig.jpg -thumbnail 100x100^ \ -gravity center -extent 100x100 cut_to_fit.gif
Ignacio linked to the correct documentation, however I'll paste it inline here for convenience:
convert -define jpeg:size=200x200 original.jpeg -thumbnail 100x100^ -gravity center -extent 100x100 thumbnail.jpeg
Similarly, the following is for GraphicsMagick:
gm convert -size 200x200 original.jpeg -thumbnail 100x100^ -gravity center -extent 100x100 +profile "*" thumbnail.jpeg
-size 200x200tells the jpeg decoder we only need this resolution so it can save memory and read the source image faster
-thumbnail 100x100^fast resize making the shortest side 100
- gravity centercenter the next operation
-extent 100x100apply the image to a 100x100 canvas
+profile "*"do not save any metainfo to the jpeg (making the resulting image smaller)
That is a simpler way to do it:
The following command resize the smaller side to 100 pixels and crop a 100x100 square. You can add a
-strip command to reduce file size.
convert original.jpg -resize "100^>" -gravity center \ -crop 100x100+0+0 -strip thumbnail.jpg
Unlike others, it isn't trying to save memory. Instead, it does what you want, and no more. Plus, it won't upscale images.
I'm using graphicsmagick to generate precisely sized thumbnails but I'm padding the image with a checkerboard instead of cropping the overhang.
gm convert -limit Threads 1 -size 320x180 pattern:checkerboard -background transparent -gravity center -resize 320x180 -extent 320x180 original.jpg -flatten -resize 112x65! -interlace Line 1 thumb_112x65.jpg
gm convert // Single threaded seems faster on smaller files -limit Threads 1 // Generate a checkerboard of size 320x180. // Sets the relative size of the checkerboard squares, // also sets the desired aspect ratio. In my case (16:9) -size 320x180 pattern:checkerboard // Resize the input image and center it on a transparent layer. -background transparent -gravity center -resize 320x180 -extent 320x180 orig.jpg // Merge the layers -flatten // Resize the output to the desired // The ! causes the aspect ratio to be ignored, fixing any rounding errors. // (Specify a size with the same aspect ratio as the checkerboard.) -resize 112x65! // Use Progressive JPEG Encoding -interlace Line // Output Image thumb_112x65.jpg
This command crop to a square and then resize to 150x150
convert 824-full.jpg -set option:size '%[fx:min(w,h)]x%[fx:min(w,h)]' xc:none +swap -gravity center -composite -resize 150x150 temp.jpg
More options are availble here: http://www.imagemagick.org/Usage/thumbnails/#square