Danbooru

What to do if we can't upload a post from an official source because there's a pixel-perfect duplicate from a third-party source?

Posted under General

It doesn't allow me to post from the official source. Do we change the third-party post's source to the official one directly or leave a comment?

Btw is bad link added by bots or manually? Its wiki says "Image links that can be converted to the page containing the image, such as Pixiv image links, don't count for this tag.", does that mean we don't always have to change its source to the post link? Or is it still preferred to do so? What about images that are found in source code but not actually on the page it's "supposed" to be from?

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If I were you, it would be better to change the source into official ones. When the original source is possible, usage of third-party source is still discouraged. After changing the source, if the official source shows larger original image, while the unofficial one has smaller resolution - try asking for image replacement on the forum. Hope the staff will replace it.

magcolo said:

Btw is bad link added by bots or manually? Its wiki says "Image links that can be converted to the page containing the image, such as Pixiv image links, don't count for this tag.", does that mean we don't always have to change its source to the post link? Or is it still preferred to do so? What about images that are found in source code but not actually on the page it's "supposed" to be from?

For some sources which Danbooru supports uploading from, bad link is indeed added automatically by bots (and as such they also remove it when it isn't valid), but outside of those cases, you can still manually add the tag. The bit in the wiki refers to the fact that some sources have source normalization - taking Pixiv as an example, you'll find that the vast majority of posts sourcing from it are in fact pximg.net/, and not pixiv.net/, because what would be the 'bad link' in this scenario has all the data necessary in the link itself for us to figure out what the original post is supposed to be. Source normalization represents the platonic ideal, where we have the image link for direct access to it but also have access to the post link, therefore not sacrificing accessibility to the original in any capacity.

It is still preferred for you to change the source to the post link though, because most sources on Danbooru are not normalized, and they're just way more accessibility-friendly. Edge cases like the one you mentioned on images hidden in source code are difficult, because one could make an argument that the source should be the image link and not count for bad link in the same fashion that we don't count it for some older styles of Japanese blogs, where they'll only have a gallery page for all images and clicking on an image takes you to the image link and not a post, but others would say that's silly and that the tag counts, or that it should be changed to the page whose source code it was taken from.

magcolo said:

It doesn't allow me to post from the official source. Do we change the third-party post's source to the official one directly or leave a comment?

Sources on danbooru should only point to md5 matches.

What do you mean by "It doesn't allow me to post from the official source"? if it redirects you to the post when you paste the file in the upload page, it means it's also a md5 match, so you can change the source freely.

If it's a pixel-perfect duplicate from a third-party source but the md5 is different, then yes, it's fine to request a replacement.

nonamethanks said:

What do you mean by "It doesn't allow me to post from the official source"? if it redirects you to the post when you paste the file in the upload page, it means it's also a md5 match, so you can change the source freely.

Yes, when I paste the image link it redirected me to the third-party post, does that mean no replacement needed?

Damian0358 said:

The bit in the wiki refers to the fact that some sources have source normalization - taking Pixiv as an example, you'll find that the vast majority of posts sourcing from it are in fact pximg.net/, and not pixiv.net/, because what would be the 'bad link' in this scenario has all the data necessary in the link itself for us to figure out what the original post is supposed to be. Source normalization represents the platonic ideal, where we have the image link for direct access to it but also have access to the post link, therefore not sacrificing accessibility to the original in any capacity.

Ah I thought it was referring to images links that are styled in a way that allows to you to track its source. Like "https://website.com/pagename/imgname.png", by erasing the "imgname.png" bit it will get you on "pagename"’s page, which usually is the image source.

Damian0358 said:

It is still preferred for you to change the source to the post link though, because most sources on Danbooru are not normalized, and they're just way more accessibility-friendly. Edge cases like the one you mentioned on images hidden in source code are difficult, because one could make an argument that the source should be the image link and not count for bad link in the same fashion that we don't count it for some older styles of Japanese blogs, where they'll only have a gallery page for all images and clicking on an image takes you to the image link and not a post, but others would say that's silly and that the tag counts, or that it should be changed to the page whose source code it was taken from.

Is it perhaps a good idea to change the source an hour after the upload? That way both the image link and the page link will be saved in the post change history. Especially for images that are hidden in source code, it’s not always easy to guess their file names.
Same for sites that don’t allow you to get access to its files when clicked on it. So even if the images are visible on the page, you’ll still have to get the files though source code.

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magcolo said:

Yes, when I paste the image link it redirected me to the third-party post, does that mean no replacement needed?

Correct, feel free to change the URL to point to a better one, if the current one is third-party.

magcolo said:

Is it perhaps a good idea to change the source an hour after the upload? That way both the image link and the page link will be saved in the post change history.

If the image is not normalizable to its post, such as a pbs.twimg.com twitter direct link, or for unsupported sites, then yes, it's fine to replace the source with the correct url as soon as you have it.
If the image is something like a pixiv or deviantart direct url and is already normalized by danbooru then you shouldn't replace those sources with their post URL, because those urls are useful for automatic md5 mismatch checks.
Think of it this way: if a danbooru post has a pixiv image url as source, and that url is from a pixiv log with 100 images, we can check it against the original simply by fetching the image url and checking if it's changed. If instead the danbooru post points to the pixiv log, then we have to fetch all 100 images and compare each of them against our image, which might not even be possible to automate properly in case of significant revisions.
We also don't know if a post url will be changed in the future. Sites like pixiv and deviantart significantly changed their post url formats over the year, so if we updated those we'd have to update them every time for every post. It's just simpler to store a normalizable url in the source field, where most users who aren't taggers won't see it, and normalize it via code when it's being publicly displayed.

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nonamethanks said:

If the image is not normalizable to its post, such as a pbs.twimg.com twitter direct link, or for unsupported sites, then yes, it's fine to replace the source with the correct url as soon as you have it.
If the image is something like a pixiv or deviantart direct url and is already normalized by danbooru then you shouldn't replace those sources with their post URL, because those urls are useful for automatic md5 mismatch checks.

Oh no I’m talking about second-party sites like a game, company or event site, not art sharing platforms. It might be a good idea to wait a few hours before changing the url, so you can see the change in post change history, that way both the direct url and the page url can be tracked. If I change the url right after uploading, it will directly replace the original url as if I never changed it, and you can’t track it anymore. This is especially undesired for images that are hidden in source code or are from sites that don’t allow you the click on images, as there’s no way to get the image url from the page url.

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