User talk:DatGuy/Archives/2020/September

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DatBot is reporting users to AIV for edit filter abuse 2 days later, even if they were blocked at the time [1]. 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)

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. — JJMC89 (T·C) 18:26, 27 September 2020 (UTC)

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 | 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)

Muzilon, 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 | 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 Guy^Talk_Contribs 21:58, 24 September 2020 (UTC)

Normal is taking longer than expected so I'll do the SVGs tomorrow. Dat Guy^Talk_Contribs 23:45, 24 September 2020 (UTC)

Thanks! Good to see the task running again. Dreamy Jazz ^{talk to me | my contributions} 00:13, 25 September 2020 (UTC)

• @Graeme Bartlett: 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 Guy^Talk_Contribs 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)

To editors DatGuy and JJMC89: 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 Guy^Talk_Contribs 18:35, 28 September 2020 (UTC)

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, IagoQnsi (talk) 18:30, 25 September 2020 (UTC)

@IagoQnsi: 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 Guy^Talk_Contribs 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. –IagoQnsi (talk) 20:41, 25 September 2020 (UTC)

I'll mess around with it a bit. Dat Guy^Talk_Contribs 18:35, 28 September 2020 (UTC)

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 ${\displaystyle {\text{new width}}={\sqrt {\tfrac {100000\times {\text{original width}}}{\text{original height}}}}}$. 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 Guy^Talk_Contribs 18:56, 28 September 2020 (UTC)

Ah! Light dawns. Thank you. Fiddle Faddle 19:00, 28 September 2020 (UTC)