DISCLAIMER: I know this forum is most about Lua, but my current project is a collab between Python and Lua via web app. I'm not featuring any Python code, but just be aware I'm using the python library requests to grab the image, and HttpService to actually utilize the image.
Ok, so, my code works perfectly fine, but right now i've been using Roblox to parse Image urls to my web app. The image urls work fine, they give the original resolution and RGBA values.
So here's where the problem comes in: I have no way to moderate the images. So I switched to Decal IDs. The web app then goes to https://www.roblox.com/library/{whatever the Decal ID is} and takes the image displayed there. So main catch is Roblox displays a scaled version of the image, 420x420 pixels to be exact.
I really really want to use Decal IDs to grab the image, but I haven't found a link to the original image, with the actual resolution. (It would always be 420x420 pixels) So anyway to actually use Decal IDs to get the actual image, with the resolution not changed? Thanks in advance :)
(I can provide any code you might have questions about, and examples of links I use in the code)

2 comments
Thanks, this was pretty useful. There's a few problems with this though; the file has no extension, and I cannot grab it with HTTPservice or request. The file extension isn't a problem really, but I don't know if there is a way to use the automatic download efficiently. I'll look into it, thank you though.
After some research I think I've got this down. Thank you for the help!