Use of ImageMagick....

[TaylorI]

Use of mogrify function in ImageMagick

Image file size will depend on the amount of data one has stored in the file and the file size get increased as image clarity and resolution get increased.
Image file size will depend on the amount of data for the image you stored in the file.

Imagemagick is a collection of tools with which you can modify, resize images on your site.

Many times site which contents many images takes a lot of time to load in a browser.
You can optimize image file size with ImageMagick.

You can confirm with the following command that ImageMagick is installed on the server
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[root@server_test]# convert -version
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After confirming that Imagemagick has been installed on the dedicated server, you can use command line tool called "mogrify" to resize images on your site.

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[root@server_test]# mogrify -resize 640x640 *.jpeg
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If you run above command it will resize all the jpeg image files to 640 pixels in width and 640 pixels in height.
First 640 will define image's width and second will define height for the image.