Thread: Image Resizing
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Old 21st January 2018
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Graham_of_Rainham Graham_of_Rainham is offline
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Re: Image Resizing

Consider the situation of the person who has an image straight from the camera at: 5568 x 3712, which is also a 3:2 aspect ratio.

To get that down to 3840 2160, 1600 x 1200, 1400 x 1050 or 1024 x 768 (or any other ratio) requires a resize... So just how do you squash 5568 pixels into 1600 pixels ?

Each original pixel needs to be interpolated by a factor of 3.48, but exactly how do you choose which method is best?

There are a lot of different algorithms, some are good at some image content and others for different content... https://en.wikipedia.org/wiki/Image_scaling

So: If you are only viewing the image on a monitor which has a different resolution to the projector, you may get a nasty surprise, on club night, when the rigging lines of the yachts in the harbour look like a staircase.

I've seen many examples of regular patterns (railings, corrugated sheeting, etc.) that when compressed takes on the look of a bar code.

I've not found a "Learned Work" from any reputable source, that provides any guidance on this. The RPS is notably quiet on the whole subject...
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