This https://i.imgur.com/0NP4IJ8.png is three exports from the same LO Draw document.
The top image is output using hardware rendering with anti-aliasing.
The middle image is output using SKIA without anti-aliasing.
The bottom image is output using SKIA with anti-aliasing.
I have always been used to the output quality of the top image. I'm quite surprised of the level of degradation in scaling SKIA puts out.
Steps to Reproduce:
1. Launch LO Draw
2. Import or copy/paste a large raster image
3. Scale the image down until it's about 1/4 to 1/5 the original size
4. Export a PNG three times using different output methods
4a. hardware with anti-aliasing
4b. Skia with anti-aliasing
4c. Skia without anti-aliasing
Only the hardware rendering option produced a crisp image. Skia-rendered scaled raster images are unacceptably blurry
The skia output option should produce as equally crisp images as hardware rendering.
User Profile Reset: No
Version: 18.104.22.168.beta2 (x64)
Build ID: 1c213561a365b5666167321de68c9977500c9612
CPU threads: 8; OS: Windows 10.0 Build 20152; UI render: default; VCL: win
Locale: en-US (en_US); UI: en-US
Created attachment 162465 [details]
LO Draw file used to create the output for this bug.
The picture quality with GDI export is already horrific. And looks like Skia is only solving the quality lack by applying anti-aliasing.
Version: 22.214.171.124.alpha0+ (x64)
Build ID: 006c65bbd472cb1d7d44e095714e28190b76be0d
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: default; VCL: win
Locale: de-DE (nl_NL); UI: en-US
Surely a bug, but not by Skia as such
This is probably caused by old, old (evil) bug. FWIW: Compare PDF export with PNG (PDF always crisp) with PNG being only good at smaller sizes
Which did remember me of bug 132590 comment 10
- Border look the same as in 7.0 PNG
- Bad quality export
- Dimensions totally (17,39cm x 27,70 cm)
- Looks the same as in 126.96.36.199
- Has the same oversized issue (12,60x10,85) Expected: 12,25 x 12,50)
- Bad quality export
- Proper size
- Proper dimensions
- Bad quality
- Oversized (12,60x10,85)
- Proper quality
- Borders OK
- Again different dimensions: 12,62cm x 10,87cm
- Bad quality export
- Borders look OK
So SVM export (dropped since....) used another code path not messing with image quality while re-compressing. Same for PDF export.. Also fine..
So with this block https://bugs.documentfoundation.org/show_bug.cgi?id=129062
that has been assigned to this bug, does that mean I need to start an education campaign for all of my users of my templates to tell them to use hardware rendering with 7.x if they expect to have sharp/crisp output of their work? And any ETA when this logjam will get cleared?
Okay, I looked up the definition of a block, and it's the opposite of what I thought it as. The other bug list won't be considered resolved until all the bugs on it are. Got it.
I still think, at least for now, that I need to add a warning on my template download pages that if people adopt 7.x to use hardware rendering.
*** This bug has been marked as a duplicate of bug 134129 ***
Would you mind retesting this.. with a daily build.. not sure if it's resolved
(In reply to Telesto from comment #7)
> Would you mind retesting this.. with a daily build.. not sure if it's
I'll download and take a look.
Not sure if it's appropriate to call it fixed necessarily, but it's definitely an improvement: https://i.imgur.com/43brkmR.png
Top image is hardware rendering, middle image is Skia without forced software rendering, and bottom is Skia with forced software rendering.
All three had anti-aliasing applied.
Skia with forced software rending is still appreciably blurred, just not nearly to the extent that it was in the first round of testing:
The question now is more of a case of what LO developers consider a close enough approximation for their own level of tolerance.
It'd be disappointing for this output to be the end-all and be-all of the result, because even with this daily build that I downloaded from your link, Skia visibly remains less than on par with hardware rendering.
Is there necessarily supposed to be a degradation in quality between the three methods (hardware/Skia/Skia forced software rendering) and that's meant to be a known and acceptable trade-off?