Bug 359128 - Add improved transformation filters (perspective transformation blurs the image)
Summary: Add improved transformation filters (perspective transformation blurs the image)
Status: CONFIRMED
Alias: None
Product: krita
Classification: Applications
Component: Tools/Transform (other bugs)
Version First Reported In: 2.9.10
Platform: Microsoft Windows Microsoft Windows
: NOR wishlist
Target Milestone: ---
Assignee: Krita Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-02-08 11:27 UTC by Odysseas
Modified: 2018-06-01 11:32 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Distort results comparison Krita - Ps (1.90 MB, image/jpeg)
2016-02-08 11:29 UTC, Odysseas
Details
video test of simple raster transformation with blurred results (3.46 MB, video/x-matroska)
2018-05-28 17:27 UTC, capricornus_gogoth_belem
Details

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Description Odysseas 2016-02-08 11:27:55 UTC
Transforming in perspective mode, or using the ctrl+alt shortcut while in free transform, results in a blurry image. Even when the distortion of the transformation is not extreme, and the layer is scaled down during the transform, the quality suffers a great deal.



Reproducible: Always

Steps to Reproduce:
1. Select a layer and go to free transform mode
2. Use the ctr+alt or the perspective mode to distort the image
3.apply

Actual Results:  
The details are blurry even when the layer is smaller than it originally was.

Expected Results:  
The details are preserved more.

Please see the attached image where this action is demonstrated in comparison to the photoshop's distort function.
Comment 1 Odysseas 2016-02-08 11:29:23 UTC
Created attachment 97083 [details]
Distort results comparison Krita - Ps
Comment 2 wolthera 2016-02-08 14:51:00 UTC
Have you tried selecting a different algorithm? I think the default is bilinear?
Comment 3 Odysseas 2016-02-08 15:06:21 UTC
Hi Wolthera, I did try all the different algorithms. The bilinear seems to produce a bit crispier results while in free transform mode, but the perspective mode remains blurry no matter what. Box makes it a bit crispier but produces some weird squarish artifacts all over.
Comment 4 Halla Rempt 2016-03-22 13:27:40 UTC
Well, I'm afraid that this is what we have currently. Someone promised to do a set of new transformation filters for us, but he never came through.
Comment 5 Alexandre Blondin Massé 2017-01-03 00:17:45 UTC
I don't know if this feature has been resolved, but I would be interested in trying to take care of it. I took a quick look to Krita's source code and I'm a bit overwhelmed by its size! If someone could just point me in the right direction (what files should I look, for instance), I'll try!
Comment 6 Halla Rempt 2017-01-03 07:06:06 UTC
Hi Alexandre,

No, this hasn't been implemented yet. The code that actually implements the filters is in libs/image/kis_filter_strategy.h. Using Qt Creator it's easy to figure out from where these filters are used. There are, for instance, four unittests in libs/image/tests:

kis_filter_strategy_test.cpp:#include "kis_filter_strategy.h"
kis_filter_weights_buffer_test.cpp:#include "kis_filter_strategy.h"
kis_processings_test.cpp:#include "kis_filter_strategy.h"
kis_transform_worker_test.cpp:#include "kis_filter_strategy.h"
Comment 7 capricornus_gogoth_belem 2018-05-28 17:27:31 UTC
Created attachment 112927 [details]
video test of simple raster transformation with blurred results
Comment 8 capricornus_gogoth_belem 2018-05-28 17:38:54 UTC
Comment on attachment 112927 [details]
video test of simple raster transformation with blurred results

Hi, guys

I can confirm the issue. It is still presented.

My OS is Solus

Kirta ver. 4.0.3

Like Odysseas said, while using transformation, it is totally enough just to rotate a selection of raster image to see that it's getting blurred. For more visible results you have to rotate a couple of times the image, which you do, when you rearranging and transforming elements of a drawing for better composition. The final result is lost edge and blurred content.  

Krita is great enough to replace Photoshop, but this issue is killing me.
Comment 9 Halla Rempt 2018-05-29 06:40:16 UTC
Yes, why do you think a wish bug in the state CONFIRMED would already be fixed? At one point Alexandre showed interest in coming up with a patch, but nothing happened. Someone will have to roll up their sleeves and start coding...
Comment 10 capricornus_gogoth_belem 2018-06-01 11:31:00 UTC
I don't know. The last comment is from the last year. I just wanted to know, is there a progress?
Comment 11 Halla Rempt 2018-06-01 11:32:20 UTC
No -- if there had been progress the bug would have been closed. Nobody is working on this.