DISCLAIMER!!! THE INFORMATION ON THIS PAGE NO LONGER WORKS!!!
While you can use a normal windows snip or do a screenshot and then edit / crop it to get a picture for the wiki, there is a way of obtaining high resolution images without extra stuff like the 'Ground' text, the enchant icon, etc. on it. This is by using a free program called Intel Graphics Performance Analyzer (or GPA).
Note that this method only works on Windows 8+ or Ubuntu 22.0.4+, so this method will NOT work on macOS.
Firstly, download and install the free program from Intel's website:
https://www.intel.com/content/www/us/en/developer/tools/graphics-performance-analyzers/download.html
Then before you run a Roblox game, start up the Graphics Monitor program. Go to the gear icon (settings) and change the General Settings for Auto-detect launched Application to ON.
Then you can minimize this program and start Roblox. You will see an overlay in the top left corner showing information, including the frame rate.
This box shows the command for listing all the keys: Ctrl+F1 It also shows information such as DirectX version, resolution, graphics card (this is on my older secondary computer), and frame rate.
To grab images for unit profile pictures, you open your inventory, select the unit, and then do a screen capture using CTRL+Shift+C. This will save the entire frame contents to your hard drive.
Please note that this isn't just a screenshot, it contains all the different data, images, textures, etc. that were using to create this screenshot within the graphics card, so each saved screenshot from GPA takes up a lot of disk space, therefore I suggest you don't keep saving them, but regularly delete ones that are not needed anymore.
Next run the Graphics Frame Analyzer program, and open your recently captured frame.
You should see a screen like the below.
Then click on a pixel on the unit's body, and it the display will change to like this:
If you don't see a side panel on the right of the screen in the above picture, you need to toggle this side panel on using this icon:
The panel on the left of the screen is showing every time that the selected pixel has been processed by the graphics card. Generally, you will want to go to the last, or bottom process, and select it:
This will open up this process into the main screen, and you will want to select the actual input image, as shown below:
This will change the main image to be just this selected input image, which will be the unit profile picture itself.
Next change the image type to RBGA which will remove the white background and make it transparent. Lastly, click the output icon to output this image to a file.
Make sure you change the output file from *.DDS to *.png.
Finally, upload your .PNG image to the wiki.
Intel also has an online help/manual area as well as training videos for this program.