Commons:Graphics village pump/August 2014

Clarification of policy for artwork

There seems to be a conflict between {{JPEG version of PNG}} (with its counterpart {{PNG with JPEG version}}) and {{SupersededPNG}}.

{{JPEG version of PNG}} displays "Generally, this JPEG version should be used when displaying the file from Commons, in order to reduce the file size of thumbnail images." Meanwhile, {{SupersededPNG}} claims "A PNG version of this file is now available" as a sufficient reason for any JPG to be superseded by a PNG. So one tells editors to use the JPG version and the other tells them to use the PNG version.

The conflict seems to arise from the fact that the former template is oriented towards paintings (which can be quite large), while the latter is for (small?) maps and other graphics. Commons:Deletion_policy#Redundant.2Fbad_quality (where "Superseded images policy" redirects) clearly states that {{SupersededPNG}}is "For raster graphics (especially JPEG) that have been superseded by PNG images" (emphasis added). Since paintings aren't "raster graphics," it seems to me that the template shouldn't be applied to them.

Scrolling through Category:PNG version available, I noticed several paintings and portraits; however, I also noticed that they seem to all have curved borders, e.g., an oval portrait or a panel with a rounded top. The PNG versions of these files have made the blank but opaque spaces in the original JPG files transparent.

I found some discussion touching on this in Commons:Graphics village pump/May 2011 (second "Oval JPGs" header), but it was inconclusive.

So my primary question is: what is the policy for which approach trumps the other? Where can I find an explanation of this policy? Can the cited policy and the templates themselves have language added to clarify their usage regarding art? Is the concern about the size of thumbnail images obsolete? And, of course, is there some other place where this discussion would be more appropriate? Thanks for any assistance. Laura1822 (talk) 16:29, 29 July 2014 (UTC)

JPEG is very useful for displaying images of paintings or other photographic type images in articles. PNG can be useful 1) Where there is a desire to archive a lossless source version of an image (without the lossy artefacts inherent in the JPEG format). 2) Where there is need for transparency or an alpha channel (not allowed in JPEG format). 3) Where the nature of the image is fundamentally non-photographic (limited number of colors, flat color areas, thin lines, sharp transitions, etc.), and so unsuitable for JPEG.

JPEG image thumbnails are auto-sharpened, which helps with photographic-type images, but would be inappropriate for diagram-type images... AnonMoos (talk) 10:02, 30 July 2014 (UTC)

Thanks. So do PNGs trump JPGs for paintings with curved borders? Laura1822 (talk) 14:53, 31 July 2014 (UTC)

Depends on whether you want a transparent background in the area outside the painting. AnonMoos (talk) 05:52, 1 August 2014 (UTC)

Clarification/update of TIFF policy

Tangential to the PNG question above, I also need a clarification or update of the policy for TIFF files as archives vs. JPEG for use.

I just came across a (fantastic) set of 20k TIFF images uploaded from a group of museums in Sweden. Category:Images from Livrustkammaren och Skoklosters slott med Stiftelsen Hallwylska museet is the umbrella category for them. These images are generally far superior to any other images of the same objects that already exist on Commons, except for a few that have also been uploaded from Google Art Project.

In particular, what I want to know is whether the paintings need to have JPEG versions created and uploaded with {{JPEG version of TIF}} and {{LargeTIFF}} tags. I left an inquiry at Commons:Batch uploading/LSH regarding whether there were any plans to upload JPG versions (since it would be extremely inefficient for editors to do them piecemeal), but since the project seems finished, I don't really expect an answer. Also, part of the goal of the project was to track usage of the files across all wikis. Therefore, unless they upload corresponding JPGs themselves, that goal will be thwarted by the creation of JPG versions.

A few of the paintings have JPG counterparts from the Google Art Project that seem to be approximately the same dimensions — see File:Porträtt, Henrietta Maria av Frankrike - Skoklosters slott - 88967.tif (3,337 × 3,913 pixels, file size: 37.41 MB) and File:Mary Villiers, Duchess of Richmond and Lennox (1622 – 85) - Google Art Project.jpg (3,338 × 3,914 pixels, file size: 5.11 MB). Would it be appropriate to pair these with {{JPEG version of TIF}} and {{LargeTIFF}} tags?

I just noticed that one of the links under source/photographer goes to the item's page at the museum's website, where a JPG image of the same dimensions as the TIFF here is available for download.

I am sure that this set of TIFF images is only one example (there are already 91 subcategories in Category:Images from museums). So what is the proper approach for using these TIFF files from GLAM sources? Should they supersede other images of the same objects? Are all the concerns about file sizes and thumbnails obsolete, or will they be obsolete in the foreseeable future, making these questions moot? If so, it seems to me that a general revision of the policy (and the various tags) needs to be addressed. Where should such a discussion be opened, if not here? Thanks for any help. Laura1822 (talk) 14:53, 31 July 2014 (UTC)

I brought these issues up here because I thought it was the most appropriate place. However, I have since done a search in the archives of the main Village pump, and TIFFs have been discussed several times there in the last few months, with no consensus on the right approach. I think that with TIFFs from GLAMs becoming more prevalent, the time is probably right for addressing these issues as a policy or guideline. At a minimum, it seems that the various templates that depend on {{Archival version}} seem to need updating. Is the main Village pump the place to propose these? Laura1822 (talk) 16:57, 31 July 2014 (UTC)

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TIFF is kind of an extendable container format rather than an image file format in the usual sense, and there's no absolute guarantee that a TIFF will have any kind of thumbnails at all if uploaded to Commons. If a TIFF does generate usable thumbnails, then opinions differ as to whether to also upload a JPEG. Sometimes the JPEG can be an edited version of the image, as opposed to the untouched raw archival TIFF. JPEG thumbnails also have automatic sharpening, which some people like... AnonMoos (talk) 05:56, 1 August 2014 (UTC)

Personally, I support to have a JPEG version in addition of a TIFF version. If one likes to download the image, it is not practical with TIFF on a slow connection (yes, these still exist). Regards, Yann (talk) 06:54, 1 August 2014 (UTC)

my svg is not rendering properly

I recently uploaded an svg file and have found it is not rendering properly. The file is here and being used on english wikipedia here. On both the file's description page and the wikipedia article the 4 wheel at the bottom there is one line missing. When viewing the svg directly in my browser (firefox) without being embedded in html, it renders missing all the circles, but the line that had been missing when embedded is now present. I've not had this issue before.

This file is a modified version of one that had been rendering w/o issues. The changes I made were to add an additional wheel/fork, by copying the first one, and editing it. I also changed all the wheel/tire circles to be grey instead of black w/ 50% transparency. The image size has also been changed. All editing has been done with inkscape. There are no embedded images in this svg, or references to them.

Any incite people can offer would be greatly appreciated. Embarrassingly I didn't notice this prior to uploading it, so as it is live on the wikipedia article, and as such I'd like to get it fixed ASAP. --Keithonearth (talk) 16:58, 10 August 2014 (UTC)

The elements of the fourth wheel all had a weird filter effect to blend the red lines with the grey arcs. I don't know if that's why some lines were being omitted, but since none of the other wheels have this effect I removed them and saved as Plain SVG, which fixed the problem of the red lines. It still doesn't explain why the grey arcs are not being displayed in Firefox. SiBr₄ (talk) 18:34, 10 August 2014 (UTC)

Thanks for your help! To make this version, I resized the 4th wheel, using a inkscape's Object -> Transform -> Scale feature. I wanted the 4th wheel to be 81% the size of the other wheels, as this corresponds with a real world size difference. I guess this produced the filter effect. I'd not realized that's how the resizing was performed. I'd like to keep it in inkscape's svg to keep the layers to allow ease of future editing. That said it's far from a complex image, so I imagine that plain svg would be ok. Any idea where to go from here? --Keithonearth (talk) 19:02, 10 August 2014 (UTC)

To me it seems very unlikely that the "Transform" menu adds the filter. You mentioned giving the wheels "50% transparency" – maybe you tried that using filters, since the arcs all are 100% opaque (the box in the lower left corner and the "Fill and stroke" menu are the usual ways to control transparency).

I just found the group that used to be the layer containing the circles and the "Smaller Wheel: Reduced trail" text also had a filter. Having removed that filter fixed the problem with these objects in Firefox. As for the layers: AFAIK the only advantage of Inkscape's layers over normal groups is the function Inkscape has to hide and lock certain layers, which can be handy for complex images but is hardly necessary for most files. SiBr₄ (talk) 19:21, 10 August 2014 (UTC)

I misread your comment about the transparency; the arcs were black and 50% transparent, and you made them grey and opaque. SiBr₄ (talk) 19:32, 10 August 2014 (UTC)

FWIW, the red lines missing in MediaWiki were also missing in Firefox; actually, the entire lower wheel was hidden. This confirms that it's the filters that caused both problems. SiBr₄ (talk) 19:25, 10 August 2014 (UTC)

Thanks for fixing that. I still don't quite understand what it is you've done. On my Inkscape I've gone into Filters -> Filter Editor and deleted the filter that was there. I also selected all and ran Filters -> Remove Filters, but the wheels are still not rendering in firefox when I load the file locally. No issues with the file you uploaded. Are you using inkskape, or are you just editing the file in a text editor (or something else?). I'd love to know how you were successful. --Keithonearth (talk) 20:00, 10 August 2014 (UTC)

I used the same "Remove Filters" button in the "Filters" menu on each object. As I said, there is one filter applied to the layer containing the grey arcs. I don't know whether it is possible to remove filters from layers within Inkscape, but saving the file as Plain SVG the first time around converted the layers to simple groups, so I could just use the button for that last filter. SiBr₄ (talk) 20:23, 10 August 2014 (UTC)

OK, thanks again for your help. I'll have to pay more attention to filters in the future. --Keithonearth (talk) 20:34, 10 August 2014 (UTC)