Help talk:Visual file markup

How to upload

I really think this page should either tell how to upload to wiki or wiki sister, or it should link there. That is really very integral to adding a pic, and I cannot find it anywhere on this page or on the page about how to edit. — Preceding unsigned comment added by 75.182.6.35 (talk) 05:08, 19 December 2011 (UTC)

Every page you see on Wikipedia should have a link named "Upload file"; doesn't that show in your environment? -- Michael Bednarek (talk) 06:14, 19 December 2011 (UTC)

Avoiding aliasing

The thumbnail default size is specified for a width of 220 pixels. So it probably would be a good idea to upload (and recommend to upload) images with a multiple of that solution to avoid aliasing artifacts.

If an image is expected to be used both in thumbnail size and without any size specification what is least common multiple of the resolutions so that aliasing can be avoided for both? — Preceding unsigned comment added by HeWhoMowedTheLawn (talk • contribs) 23:43, 3 March 2012 (UTC)

I think this is a valid question, anyone listening? --HeWhoMowedTheLawn (talk) 20:31, 25 August 2012 (UTC)

You could try posting at Village pump (technical), where your idea would be seen by more of the project's technical people. -- John of Reading (talk) 08:04, 26 August 2012 (UTC)

See also Wikipedia:Village pump (technical)/Archive 98#JPEG size. Bear in mind that any change to the resolution of an image compressed using a lossy algorithm - such as a JPEG image - will deteriorate the quality, so this should be done as little as possible. In other words: if there is the slightest possibility that the image will be resized at a later date, don't pre-emptively resize it. --Redrose64 (talk) 15:06, 27 August 2012 (UTC)

I do not think my point has been taken and it is still not addressed in the article. I do not want to resize an image. I want to size an image. This is: I'm free to generate a diagram with an arbitrary width and an arbitrary height. Which should I use? Rephrasing: which width and height would be least likely be subject to aliasing? HeWhoMowedTheLawn (talk) 21:36, 14 May 2013 (UTC)

For photos: upload the image at whatever size your camera or scanner generates. Crop it prior to upload if you like; but don't attempt to enlarge or reduce, since the Wikipedia image syntax allows pretty much any size to be used in the final article. Also don't convert it to or from a JPEG, leave it in the native format.

For diagrams: stay away from JPEG - ideally, use SVG format, but if the diagram is not really suited to SVG, or you are unable to prepare a SVG file, use the PNG file format, which (like JPEG) is raster graphics, and (unlike JPEG) uses lossless compression. --Redrose64 (talk) 23:03, 14 May 2013 (UTC)

Hi Redrose64, thanks for commenting but your answer does not address my question. Repeating my (already rephrased) question for convenience:

HeWhoMowedTheLawn (talk) 20:41, 16 May 2013 (UTC)

There's no need to repeat, I read it. What is the image that you want to upload? Is it a photograph, or a line drawing, or what? That affects the file format, which itself may or may not affect choice of optimum size. --Redrose64 (talk) 21:19, 16 May 2013 (UTC)

Isn't the way an image is rendered in a browser a matter between the browser and the hardware it's running on? Further, the uploader has no control over the scaling other editors chose to show the image in an article. -- Michael Bednarek (talk) 02:12, 17 May 2013 (UTC)

It's an svg which I want to update Operating_systems_used_on_top_500_supercomputers.svg. It has a native resolution of 1000x700 which can be set in line 12 of the gnuplot script. The aliasing effect is for example visible at the vertical lines of the 800x560 preview. HeWhoMowedTheLawn (talk) 06:08, 17 May 2013 (UTC)

Well, it's a SVG, so the size is immaterial, since it's infinitely scalable. The size is defined at point of use, see the extended image syntax. There is software on the server (I believe that it's librsvg) which will convert the SVG to a PNG of the width so specified, and it is that PNG which is actually placed into the Wikipedia page. It doesn't really matter what you put in the width="1000" height="700" attributes of the <svg> tag since these are ignored - you could put width="10" height="7" and it would make no difference.

I notice that your SVG image has a transparent background. If the problem that you see is that the transparent area kind of eats into the edges of the non-transparent area, you could set an explicit white background. Insert the following line:

<rect x="0" y="0" width="1000" height="700" stroke="none" fill="white" />

in between the existing </defs> and the first <g style="..."> --Redrose64 (talk) 11:22, 17 May 2013 (UTC)

I'm well aware of svg being infinitely scalable. Yet if it is converted to a pixel representation you can get aliasing. --HeWhoMowedTheLawn (talk) 17:31, 17 May 2013 (UTC)

No, the problem is visible at the vertical lines of the 800x560 preview. Not at area to area transition. Other diagrams with non-transparent background show the same effect. Picking an arbitrary one off Category:Images_including_source_code_in_their_description with non-transparent background. This one File:Conic x^2+2xy+y^2−8x=0.svg shows the vertical dotted line at +7 blurred compared to the one at +8. --HeWhoMowedTheLawn (talk) 17:31, 17 May 2013 (UTC)

OK, I'm going to admit that I'm out of my depth. The technical aspects of image format conversion are not my field; and in any case, this is the wrong venue for making such queries. It is the talk page for discussing improvements to the page Help:Visual file markup, which does not cover the upload process itself, but concerns the means for adding an image which has already been uploaded into an article. I don't actually know what the correct venue would be on Wikipedia; there is one on Commons that I know of, it is commons:Commons:Graphics village pump. We do have Wikipedia:Preparing images for upload but that's not a forum. Something like nine months ago, you were advised by John of Reading (talk · contribs) to post at WP:VPT, but I cannot find any evidence that this was ever done. I have now raised a thread there asking for others to assist. --Redrose64 (talk) 19:40, 17 May 2013 (UTC)

Sphilbrick (talk · contribs) suggests that Wikipedia:Graphics Lab may have editors who can help. --Redrose64 (talk) 11:33, 18 May 2013 (UTC)

Thanks, I asked there. --HeWhoMowedTheLawn (talk) 21:08, 21 May 2013 (UTC)

Oops, sorry mistakenly asked here Wikipedia:Village_pump_technical --HeWhoMowedTheLawn (talk) 21:18, 21 May 2013 (UTC)

Example.png

This file appears to have been overwritten with some warning text- hardly helpful. would it be better to just replace all the File:Example.png examples with File:Flag of Japan.svg?--ClemRutter (talk) 10:17, 12 April 2016 (UTC)

Looking at the 7px to 20px change, I am distracted by the example. Most people expect a flag to be in the 2:3 format, as seen in File:Civil Ensign of Hungary.svg- the 2:1 format may comply with Hungarian law- but does it offer any clarity advantage here. Can I suggest that File:Flag of Hungary vertical.svg be replaced. ClemRutter (talk) 23:37, 25 May 2017 (UTC)

Frameless doesn't work!

Unlike German "rahmenlos" on German Wikipedia "frameless" doesn't work. images still have their caption here. See Amenemhat I and de:Ebers-Kalender e.g. --Vollbracht (talk) 18:06, 18 January 2022 (UTC)

It works as expected. The text visible in the frame below the infobox as the second image at Amenemhat I, "Cartouche of the …", is not part of the [[File:…, which ends at …|185px]], but part of the table. -- Michael Bednarek (talk) 05:53, 19 January 2022 (UTC)