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Bug #4885
closedRedux image quality is poor / produces artifacts in imageviewer.php
Status:
Closed
Priority:
Normal
Assignee:
Category:
-
Target version:
Start date:
04/05/2017
Due date:
% Done:
0%
Estimated time:
Affected Version:
Appion/Leginon 3.2
Show in known bugs:
No
Workaround:
Description
When the image viewer was originally created it was taking images from 4096 to 512, which is integer scaling. With newer EM camera the scaling has become a float and introduce artifacts.
Two things I noticed to fix this:- scale by float then integer could help.
- use bilinear scaling rather than default bicubic
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Updated by Neil Voss over 7 years ago
- Status changed from Assigned to In Test
- Assignee changed from Neil Voss to Anchi Cheng
new method should be faster and reduce artifacts from scaling.
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#2
Updated by Neil Voss over 7 years ago
- File old_method.jpg old_method.jpg added
- File new_method.jpg new_method.jpg added
Updated by Bridget Carragher over 7 years ago
Looks better to me for sure. But what about speed etc.?
Updated by Neil Voss over 7 years ago
- File redux_testing.pdf added
By my tests, the scaling goes ~3.5X faster. Quality goes up with more noise in the images (see attachment)
We are not longer doing a cubic fit for each pixel, just a linear fit, so that goes faster. Bicubic interpolation is the default in Adobe Photoshop, but does not work well with noisy images.
Updated by Neil Voss over 7 years ago
- File redux_testing.png redux_testing.png added
Updated by Anchi Cheng about 7 years ago
- Status changed from In Test to Closed
- Target version set to Appion/Leginon 3.3
Works well
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