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Major image hosting problem


fizzymagic
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4 hours ago, thebruce0 said:

 

I can also vouch for at least one puzzle that would definitely be broken by converting to webp :)

 

Yeah, I had not thought about the "append-a-zip-file-to-a-jpeg" puzzles.  Those would break.

 

Maybe (here's an idea) leave them in the format in which they were uploaded!

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11 hours ago, mustakorppi said:

The attached gif contains hidden coordinates. Here's the same image in webp, converted using the gif2webp tool from newest libwebp. It is smaller than a progressive jpeg would be, but it breaks the "puzzle" just the same.

You'll note that I did not mention paletted images in my post.  For whatever reason, GIFs are being preserved by the current system.  WebP has no alternative to animated GIFs and I don't  know if it has a paletted mode.  Conversion would require preservation of the palette, for both paletted PNGs and GIFs.  Which is why just leaving the images alone is the optimal solution!  I am fine with size reductions if the images exceed some maximum storage size, as long as it is make clear on the image upload page.  Right now, the most violence is being done to PNG images, although appending data to jpegs probably breaks as well.

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2 hours ago, fizzymagic said:

WebP has no alternative to animated GIFs and I don't  know if it has a paletted mode.

Webp does support animation and from what I understand it has some kind of a palette mode, but I’m not aware of any tools that would let you mess with it.

4 hours ago, ecanderson said:

All I'm seeing with Firefox 83.0 is blank white

Hence, ”hidden coordinates” :) As fizzymagic hinted at, that gif image has two colors in its palette. Both of the colors are currently titanium white but if you mix in some van dyke brown with the other one, you’ll get happy little treesthe coordinates.

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5 hours ago, sernikk said:

Geocaching.com is still treating Waymarking.com as an enemy and is not allowing to paste any images from there.

As an example, it is impossible to use the official logo: https://www.Waymarking.com/images/logo.gif as an image. Shouldn't this be fixed by now? I remember the discussion about it.

The obvious implication is that Waymarking.com places nefarious advertising cookies on people's browsers.

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On 12/3/2020 at 12:19 PM, sloth96 said:

So does anyone have a list of steganography tools that  survive this transcoding? Outguess and silenteye are two that i have seen recently for puzzles.  

 

Outguess barely survives anything; silenteye is probably a little better.

I don't like using canned steganography that requires (as those do) downloading a program.  I much prefer rolling my own that people can figure out how it's done instead.  I have recently done some GIF stuff that would survive but I think it might be too difficult as a puzzle until I think of something clever to make it work.

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