Resizing images for use in Canvas on low bandwidth connections

 When images are uploaded to Canvas the images retain their original size in terms of memory consumed. 


By way of example, the original image for the above image is 4000 × 2250 that requires 1,945,277 bytes (1.9 MB on disk). When uploaded to Intructure Canvas LMS for use in an Assignment, Quiz, or on a Page the original size is retained.


The original 1.9 MB file is the second one listed. The first file listed is a rescaled (resized) image reduced to 960 × 540 using the free open source photo editor Graphic Image Manipulation Program. The Graphic Image Manipulation Program is a cross-platform package with versions for Linux, Apple OSX, and Windows.  Both files were added to a Page in Canvas via the usual image upload option. 


Prior to uploading an image I use the Scale Image... option in GIMP to resize images. I use this option so often that I have assigned a keyboard shortcut to the option. The resized image requires only 159,636 bytes (160 KB on disk). This is a factor of twelve reduction in bytes required to be transmitted. All other factors being equal, this image should load twelve times faster than the original. The loss in resolution will not be noticed on a mobile device. There is little obvious impact even on a laptop. 


If you have students who are working over a connection with limited bandwidth, rescaling images greatly benefits the student. 



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