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Lecture 4: Transforms (6)

Non-uniform scaling here reminds a lot about the small design work I do in creating Instagram content. Whenever I'm tryna reduce a picture in size, but only on either a horizontal/vertical side, this picture becomes more squished and doesn't retain it's full original form, similar to how it looks on this clock here.


When we shrink large images and then subsequently enlarge it (in google docs etc), how does the image retain its original quality?


@lwg0320, I think they keep the original data around to help you perform non-destructive editing! Photoshop often works similarly. When pasting or dropping an image into Photoshop it typically becomes a 'Smart Object'. These Smart Objects retain their original data, so you can squeeze, un-squeeze, scale, and so forth while retain original image quality. So the current image shown is really just a preview, and when you adjust it again all the math is recalculated from the original source data. If you want to actually burn in the data in Photoshop, there is an option to 'Rasterize' the layer! That will make those changes destructive and original quality will not be maintained. I imagine Google docs does something similar!

Here are some links on the specifics within photoshop:,text%20on%20a%20type%20layer.


I was interested in how non-uniform scaling is used in real-world applications besides graphics. There are many exciting applications from geographic information systems to biomedical applications. Doctors can use non-uniform scaling to get more accurate MRI scans of their patients and get better dimensions of organs.

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