Here I have created the .sbmp file extension. It stands for Scratch Bitmap Image File, but only the Scratch Bitmap part is in the extension.

To get started, download the repository. Make sure you have python and pip installed.

Next, install the dependencies. pip install -r requirements.txt

Then, on Windows, set up the viewer.py to view .sbmp files. This can be done by:

Start Menu -> Default Programs -> Type '.sbmp' and click Choose a default -> Navigate to the downloaded repo -> Choose sbmpViewer.bat

Now, double-clicking any .sbmp file will open with the viewer.py file.

Converting files is quite easy. In the directory of the repository, open a terminal window.

Type python converter.py <filename.jpg/png> <size [preferably something like 240 or 360]> <output filename .sbmp>

You can then double-click them to view (if you have done the previous steps)

The entire purpose of .sbmp files is for them to be able to be viewed on Scratch. So, here's the link to the .sbmp viewer.

https://scratch.mit.edu/projects/1107520357/

Inside the project, show the .sbmp upload list, right-click it and click import. Then, change to all files in File Explorer, and select the output.sbmp file from your folder. Finally, run the project with a green flag or click the custom block. This will render the sbmp file to your screen.

You may have realised Scratch already offers this functionality, to be able to add images to your project. That's why this has a reason: ScratchAttach Cloud Requests.

ScratchAttach (by @TimMcCool) has a feature named Cloud Requests that allow data to be transferred between the Scratch project and a python backend. This means that we can use it to transfer the .sbmp file, after converting it, through the project and rendering it.