linux imagemagick draw on existing image

If you have a huge collection of images to convert, use IM’s mogrify utility with the -format switch: You can change a JPG file to PNG with a command such as convert one.jpg newone.png. The -flip switch produces an upside-down image of the original while the -flop switch turns the image on a vertical axis. If you wish to rotate the image counter-clockwise, use a negative number. The -rotate switch, by default, rotates the image clockwise by the number of degrees specified. ImageMagick maintains the aspect ratio of an image, which results in symmetric images.Ĭonvert can also rotate or flip an image:Ĭonvert -rotate 90 image_0001.tiff output.tiff You can also specify percentages instead of pixels by using syntax such as convert -sample 30%x30% big.jpg thumb.jpg. sample tells IM to scale the image using pixel sampling. Here, big.jpg is the input image and thumb.jpg is the output image, which is to be 80×60 pixels. To convert one image into a thumbnail for my blog, I ran the command convert -sample 80圆0 big.jpg thumb.jpg.

In addition to changing the size of an image, convert can convert it from one format to another (IM supports almost 90 different image formats), rotate an image, and add effects to an image. IM packs a nifty utility, convert, that can handle this. With ImageMagick (IM) you can crop your image, change its shades and colors, and add captions, among other operations. But can you manipulate images without switching to the GUI and using the resource-hungry GIMP? You can, using the fantastic ImageMagick suite. For many a GNU/Linux user, the command line is supreme.

Linux imagemagick draw on existing image