For image processing via Neural Networks, I suggest you to follow: https://becominghuman.ai/image-processing-with-deep-learning-a-quick-start-guide-38e166340200?gi=88a1f3bcdc86

https://www.mathworks.com/help/deeplearning/ref/trainingoptions.html

https://www.mathworks.com/help/stats/classification-using-nearest-neighbors.html

https://machinelearningmastery.com/how-to-develop-convolutional-neural-network-models-for-time-series-forecasting/

Auto-encoders have successfully been used to compress thumbnail images where JPEG compression struggles because of the very low resolution. I really don't have a clear idea of what you are asking but this is muy best guess.

Article Variable Rate Image Compression with Recurrent Neural Networks