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Bug 87450 - SVG reduced in quality and distorted
Summary: SVG reduced in quality and distorted
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
3.5.0 release
Hardware: All All
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords: filter:svg
: 112469 (view as bug list)
Depends on:
Blocks: SVG-Import
  Show dependency treegraph
 
Reported: 2014-12-18 17:01 UTC by Shimi Chen
Modified: 2018-12-11 19:31 UTC (History)
3 users (show)

See Also:
Crash report or crash signature:


Attachments
odp file in which the bug can be seen when presenting (46.42 KB, application/vnd.oasis.opendocument.presentation)
2014-12-18 17:01 UTC, Shimi Chen
Details
Only the isolated png image (262 bytes, image/png)
2018-06-18 15:24 UTC, Regina Henschel
Details
Only the isolated svg image (32.02 KB, image/svg+xml)
2018-06-18 15:45 UTC, Shimi Chen
Details

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Description Shimi Chen 2014-12-18 17:01:35 UTC
Created attachment 110994 [details]
odp file in which the bug can be seen when presenting

The attached file looks fine in normal view but when hitting F5 for presentation view, the image becomes blurred and the important information is lost.

The image is an imported SVG file.
Comment 1 Robinson Tryon (qubit) 2014-12-24 04:30:57 UTC
TESTING with LO 4.4.0.1 + Ubuntu 14.04

(In reply to Shimi Chen from comment #0)
> The attached file looks fine in normal view but when hitting F5 for
> presentation view, the image becomes blurred and the important information
> is lost.

CONFIRMED: image becomes very blurred (in a neat, artistic way, as it turns out, but that doesn't change the fact that we have a bug :-)

Totally weird!

Status -> NEW
Comment 2 QA Administrators 2016-01-17 20:03:25 UTC Comment hidden (obsolete)
Comment 3 Shimi Chen 2016-01-18 11:30:46 UTC
Bug still occurs in 5.0.4 with the example file.
Regarding regression testing, with 3.3 the svg does not work at all. As far as I can tell native svg import was introduced in 4.0.

I tested 4.0.0.3 and it's interesting. The blurred image appears both in presentation mode but also in editing mode. So somewhere between 4.0.0.3 and 4.3.4.1 it was fixed for editing mode but not presentation mode.
Comment 4 QA Administrators 2017-03-06 14:08:53 UTC Comment hidden (obsolete)
Comment 5 Shimi Chen 2017-03-06 14:20:45 UTC
Bug behavior has changed in 5.3.

Previously, the SVG was displayed correctly in editing mode and incorrectly in presentation mode.

Currently (5.3.0.3), the SVG is displayed incorrectly (smeared) in both modes.
Comment 6 Xisco Faulí 2017-10-01 22:50:45 UTC
*** Bug 112469 has been marked as a duplicate of this bug. ***
Comment 7 Regina Henschel 2018-06-18 15:24:59 UTC
Created attachment 142870 [details]
Only the isolated png image

The error is not a problem of svg. The attached file contains an embedded png-image, which is scaled up by a transformation. The image itself has 11x11 pixels. I have extracted the image from the file and attached it.
If you insert this small image and scale it up, you will see the same. The rendering is independent of Antialiasing on/off.
Comment 8 Shimi Chen 2018-06-18 15:45:42 UTC
Created attachment 142871 [details]
Only the isolated svg image

Yes, it appears that LibreOffice automatically converts the svg to a png and the resulting png file is deformed. The original svg is also included in the odp archive next to it (attached), and shows the correct image if opened in Inkscape for example.

I now see that Eye of MATE also shows the distorted image if the svg is opened, so this is likely an issue with some common upstream library (librsvg?). Does LibreOffice indeed use librsvg? At any case, I will work on submitting it as a bug with librsvg as it does distort the image when converting it to png.
Comment 9 Regina Henschel 2018-06-18 15:58:48 UTC
The svg-file itself has the image as embedded png. It is the part

        <g transform="matrix(34.7273,0,0,31.1818,64,31)" style="fill-opacity:0; fill:rgb(0,0,0); text-rendering:optimizeSpeed; color-rendering:optimizeSpeed; image-rendering:optimizeSpeed; shape-rendering:crispEdges; color-interpolation:sRGB; stroke:rgb(0,0,0); stroke-opacity:0;" >
            <image x="0" y="0" width="11" xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAsAAAALCAIAAAAmzuBxAAAAzUlEQVR42i2QWxHE IBRD4wAJlVAJlVAJKwEJSKiESkBCJVQCEpCQPWF3hg+4yc0DedcluUjqOtzcHh+6 XDw1fLprSLf0QNAE5q5iWy+ruxW8ZM+PmKwNa3M1uq9PqcLF4pCrQD0gbFhoOrqP QYUdS27Z8Z0lOJzbHw5Q7He/m0fXUqpCAyVQcmBNzkihny63gZlSh+zTpZOFRxLt KUbeC5G27EvYTasqhwR8AErkTfNu2i7hseBlkQS/4TR3CsNO//UtSRCvaIlx2H+P +QWSoailUww0wQAAAABJRU5ErkJggg==" style="clip-path:url(#clipPath2);" height="11" preserveAspectRatio="none" />
        </g >

You can see in the matrix, that it is extreme up-scaled. The question is, how such up-scaling is done.
Comment 10 Shimi Chen 2018-06-19 08:20:52 UTC
Ah, thanks for that. Now I see also that in Inkscape when selecting the image it is easy to change between the distorted and non-distorted views.

This is done by switching the Image Rendering mode between optimizeSpeed (shows the *correct* image) and optimizeQuality (shows the *distorted* image). The svg file specifies that the image should be displayed using optimizeSpeed, and LibreOffice apparently ignores that?

Or perhaps there is no standard way to implement optimizeSpeed and Inkscape happens to use a method which shows the intended result?
Comment 11 Timur 2018-12-06 13:23:43 UTC
Can't say why it was marked Linux. Also repro Windows. LO 3.5 and 6.3+.