Image Quality Decrease and pixelated
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The quality of the image decrease when I read and display out in matlab, please advice.
The below are the commands that I had used: imread,imshow
Image Info: Format:JPEG Dimension:1,434 x 1,014 Size:487KB
1 Comment
Adam
on 1 Dec 2014
Try using image or imagesc instead, depending if you have full R, G, B data or just indexed data.
I never use imshow as it always seems to give appalling results.
Accepted Answer
Image Analyst
on 1 Dec 2014
I don't know what Adam does with imshow() but it works fine for me and is my preferred method, unlike imagesc() which applies some colormap that you didn't ask for. Don't use pcolor - that's even worse. Anyway, why do you say the image quality decreases. Show me a screenshot of the image in imshow() and in some other program (like paint or Photoshop) so I can see why you think it's worse. It should display it exactly as it was stored on disk, just magnified or demagnified for display of course. Of course you may have stored a horrible image where you jpegged the heck out of it and it shows up with horrendous jpeg block artifacts, but that would be present in any program that displays it.
11 Comments
Eric Auth
on 12 Apr 2018
This is the best I can do. Taken a super small crop of the initial .tiff and zipped it with Adobe Photoshop (which changed to .tif) and then into a zip folder. Original .tiff image is 118 MB.
DGM
on 5 Feb 2023
I know it's too late, but I saw this while cleaning up. There's a bunch of Photoshop metadata in that file, the purpose of which I don't understand. There is an included ICC profile, but there's also a 1x4236 numeric vector embedded by Photoshop. So... more profile data?
Maybe in another five years, someone will tell us what it all means.
More Answers (2)
meola22
on 2 May 2017
Edited: meola22
on 3 May 2017
Just stumbled upon the same problem and the solution is quite simple. All one needs to do is change the OpenGL from software to hardware. So just add this line of code:
opengl hardware
That fixed the pixelation problem for me.
1 Comment
Eddy Philippe
on 4 Mar 2022
This improved it, thx! It's still not 100% perfect resizing (as I get i photoshop), so I'm still working on it.
Jose
on 23 Feb 2022
A mitigation to a pixelated image display may be interpolation available from R2019b:
figure;
subplot(121); imshow('logo.tif')
subplot(122); imshow('logo.tif', 'Interpolation','bilinear')
I use it to display text pages converted to images.
My thanking to Steve Eddins:
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