>Sparked off by http://meta.gardening.stackexchange.com/questions/251/better-image-embeddeding-and-viewing, http://meta.diy.stackexchange.com/questions/549/change-the-image-upload-so-that-a-thumbnail-is-shown-and-the-full-size-image-lin
>
> Thanks to @yoda for the idea!

When you upload an image using the SE uploading dialog, it gets uploaded in _exactly_ the same size that the file is in. For large images, this can be a problem since they take up a lot of space and screw the alignment. The uploader doesn't allow for resizing (except by manually changing the URL to one ending in `s`, `m`, or `l`.

This script provides an improved upload dialog:



![enter image description here][1]
##Installation##

 - [Click here to install][2]. Will only work in Chrome or Firefox (the latter requires Greasemonkey).

 - [Source][3]

##Usage

I haven't made it hijack the image upload button yet (I may do this later, I don't want to destroy a user's image uploading capability if this has a bug). It has its own button, marked with a "T" in the editor toolbar. 


The small/medium/large use Imgur's special `s/m/l` URLs (if you append `s`,`m`, or `l` to the URL, you get a resized version of the file).

Note that `medium` and `large` do not work is the width of the image is less than 640 and 32o px respectively. `small` will force the image to be a 90×90 square, downscaling/upscaling and cropping it in the process if necessary ([source][4]). Use the option described immediately below if you would like to bypass these restrictions.


If you want even more control over the image size, use the height/width textboxes, which generates an `<img>` tag (allowed in MarkDown). Leaving one of the two textboxes blank will preserve aspect ratio.

Additionally, there is a very useful "link to fullsize" option at the bottom, for creation of true thumbnails.


  [1]: https://i.sstatic.net/7VwY4.png
  [2]: https://github.com/Manishearth/Manish-Codes/raw/master/StackExchange/ThumbnailUpload/ThumbnailUpload.user.js
  [3]: https://github.com/Manishearth/Manish-Codes/blob/master/StackExchange/ThumbnailUpload/ThumbnailUpload.user.js
  [4]: http://meta.stackoverflow.com/a/108821/178438