1 (edited by testyou 2011-09-17 20:46:15)

Topic: High Quality Resizing

Hello Michael.

I have recently been testing IA for upscaling high quality images by 2x.
My chain has involved:
1.  Editing and balancing the files as necessary.
2.  Performing Wiener m=4 upscale by 200%.
3.  Sharpening via the Deconvolution by Circular Blur method,
     using a very small radius and one iteration.

Do you think that these are the best options for upscaling HQ images?

Wiener m=6 produces more blurry images.
The other resize methods do not seem to outperform Wiener.
The Fractal plugin creates artifacts.
I choose Deconvolution by Circular Blur due to the artifacts from using
    the Sharpen filter.
The details from Wiener resize seem better suited to Deconvolution.
The Wiener resize produces details which are similar to fractal
    artifacts, but seem more natural.

Do you have any recommendations or advice?

2

Re: High Quality Resizing

It sounds like a reasonable approach.
You might want to try the Warp sharp resize method in the Advanced filters plugin pack. It also has a Warp sharpen method you could compare with the deconvolution.
See http://logicnet.dk/Analyzer/plugins/ind … cedFilters

Michael Vinther

> software developer <

3 (edited by testyou 2011-09-20 1:07:15)

Re: High Quality Resizing

Thank you.
I found the warp sharp resize too destructive, so I didn't mention it.
Now that I've been playing with the warp sharpen, when used very lightly on low settings,
    I can obtain results that I am more pleased with than when I first tried it.

I think that I will have to try each method with different settings to find which one
    suits the particular image best.

The examples I've used show the Wiener 4 gives the best balance of quality and faithful results.

I hadn't seen a Wiener method before I found your program, is it unusual to implement?
Lanczos 2 or 3 was what I used most frequently but I did not enjoy the halo effect.
I am very impressed with Wiener 4.

4

Re: High Quality Resizing

I haven't seen the Wiener method in other software either, but it might exist under a different name.

Michael Vinther

> software developer <