User talk:DatGuy/Archives/2020/September

DatBot issue
DatBot is reporting users to AIV for edit filter abuse 2 days later, even if they were blocked at the time. I just removed a bunch of reports, but I haven't seen something like this before and wanted to give you a heads up. Best,  Spencer T• C 18:13, 17 September 2020 (UTC)

Bot malfunction
Hi - I believe your bot keeps continually distorting File:Newspaper Carriers, Columbus, Ohio.jpg, thought you should know. ɱ (talk) 14:54, 27 September 2020 (UTC)
 * It may have something to do with the rotation in the metadata. I've manually reduced it. —&thinsp;JJMC89&thinsp; (T·C) 18:26, 27 September 2020 (UTC)

non-free file reduction task
Hi. I've noticed the task hasn't still yet resumed, though I noticed you said you would look at it in July. Do you have any update when the task might restart? Dreamy Jazz talk to me &#124; my contributions 23:00, 19 September 2020 (UTC)
 * I was also going to ask about an unfulfilled request for a non-free image reduction... I'm guessing there may be an issue with the bot then? Muzilon (talk) 21:09, 22 September 2020 (UTC)
 * , it hasn't run since the 11th of July and from User_talk:DatGuy/Archives/2020/August it seems like there is an issue with it. I'm guessing there is still an issue with said task, but the bot itself is still running. Dreamy Jazz talk to me &#124; my contributions 21:01, 24 September 2020 (UTC)
 * I'm running normal resizing automatically and then will go one-by-one for SVGs to make sure it's all fine. Dat GuyTalkContribs 21:58, 24 September 2020 (UTC)
 * Normal is taking longer than expected so I'll do the SVGs tomorrow. Dat GuyTalkContribs 23:45, 24 September 2020 (UTC)
 * Thanks! Good to see the task running again. Dreamy Jazz talk to me &#124; my contributions 00:13, 25 September 2020 (UTC)


 * Do you know why the SVG for File:2020 Stanley Cup playoffs logo.svg has values of 236x255 but the Wikipedia resolution is 512x553? It's very odd and messes up with the bot's ratio. Dat GuyTalkContribs 18:13, 25 September 2020 (UTC)
 * I don't know why that is the case. I reverted the sizing to 141 × 152 as that was too small. For .svg files the actual size of the display hardly makes a difference to minimal use. Instead a .svg reduction should be removing small detail. But for logos there probably isn't any. Graeme Bartlett (talk) 21:53, 25 September 2020 (UTC)

Is the goal of the size reduction request and completion to reduce the file size or the pixel size? I ask because File:'Mazing Man no1 cover.jpg was reduced in resolution, but the file size ended up increasing. I don't particularly care if the resized image is maintained, but I'm just curious. -2pou (talk) 18:17, 28 September 2020 (UTC)
 * The objective is to rescale the image. Smaller file size would be preferred (and possibly expected) but not required. Dat GuyTalkContribs 18:35, 28 September 2020 (UTC)

Poor quality JPEG reduction by DatBot?
Hi DatGuy, I recently noticed that when DatBot reduced the size of File:Eligible novel cover.jpg, it seems to have used a low value for JPEG quality. The compression artifacts are pretty noticeable, and I ended up manually resizing it myself to replace the DatBot version. Granted, the image in question features a solid-color background and is a bit of an edge case for compression, but I had previously just assumed the bot always used quality=100. Is this intended behavior? Thanks, Iago Qnsi  (User talk:IagoQnsi) 18:30, 25 September 2020 (UTC)


 * The bot resizes it with a Lanczos filter, which as far as I know is the best. The quality thereafter is set to 95, as the documentation states that "values above 95 should be avoided; 100 disables portions of the JPEG compression algorithm, and results in large files with hardly any gain in image quality." Dat GuyTalkContribs 19:34, 25 September 2020 (UTC)
 * I would tend to disagree with that bit of the documentation -- if you compare my second upload to DatBot's upload, there's a significant difference. Serving a compressed version for end users is MediaWiki's job; there's no real need for uploaders to try to reduce file size. – Iago Qnsi (User talk:IagoQnsi) 20:41, 25 September 2020 (UTC)
 * I'll mess around with it a bit. Dat GuyTalkContribs 18:35, 28 September 2020 (UTC)

File:ISSA Logo.png was flagged for reduction, but increased in size
Is that reasonable, pleease? Fiddle  Faddle  18:39, 28 September 2020 (UTC)
 * The bot isn't really a downsizing bot, but rather it's target is "to make the image as small as possible to still be useful as identified by their rationale, and no larger." It's been decided for now on Wikipedia that 100000 pixels should be enough for non-free images. As such, the formula for finding the width (and therefore the height, as the ratio stays the same) is $$\text{new width} = \sqrt{\tfrac{100000 \times \text{original width}}{\text{original height}}}$$. In the case of your image, the formula results in a width of 608 pixels which leads to height of 164px, 608 * 164 = closest number to target of 100000 pixels. Dat GuyTalkContribs 18:56, 28 September 2020 (UTC)
 * Ah! Light dawns. Thank you.  Fiddle   Faddle  19:00, 28 September 2020 (UTC)