PNG data without saving to file?

[nchen]

Hello,

Is there a way to convert a layer to PNG data, and convert PNG data to a layer, without exporting to a file?
I am trying to send a layer to a local server that accepts base64 encoded PNG data, receive base64 encoded PNG data, then convert that data back into a layer.

My current process is as follows:
> Save layer as PNG (pdb.gimp_file_save) 
> Read the PNG file data
> Convert PNG data to base64 data
> Send base64 data using websocket 
> Receive base64 data
> Write the received data to the previously saved PNG file 
> Load the PNG file as layer (pdb.gimp_file_load_layer)
> Delete PNG file

The closest solution that I have found is to use PIL/Pillow. I have tried installing PIL6.2.2 and earlier versions with GIMP's python but receive the error:
"The headers or library files could not be found for zlib, a required dependency when compiling Pillow from source."


If there is a solution within GIMP, or someone might be able to help me get Pillow to work, I would greatly appreciate it!
I am on Windows 10, using GIMP 2.10.38, and GIMP's Python 2.7.18. Please let me know if there is additional information I should provide.
Thank you for your time!

[nchen]

For context: I'm working on making a plugin that communicates with ComfyUI.
Getting an answer for this would be great, as it would be compatible with existing nodes. I realize, however, that I can just create a new node that accepts GIMP layer data, which I have just done.

[Ofnuts]

No, unless you want to rewrite your own plugin. 

Using a temporary disk file is not as bad as it looks, because with PNG the encoding is very slow (so you aren't adding that much time with the file I/O in a decent OS).

If you can transfer the raw data (or something close such as BMP or Targa) you can get the layer as a python array using pixel regions.

[nchen]

(09-10-2024, 12:19 AM)Ofnuts Wrote: No, unless you want to rewrite your own plugin. 

Using a temporary disk file is not as bad as it looks, because with PNG the encoding is very slow (so you aren't adding that much time with the file I/O in a decent OS).

If you can transfer the raw data (or something close such as BMP or Targa) you can get the layer as a python array using pixel regions.

It looks like pixel regions is the best answer. The one issue I find with a temporary file is that it bloats the PF_IMAGE option selection with all of the deleted images.

By the way, your high quality documentation throughout time has been instrumental in my development. Thank you so much!