Home-made tvorog is just cottage cheese without the temperature or fermentation control, you just let the fresh milk get sour and curd on it's own then strain the curd. So it's more acidic and less uniform.
The commercialy produced tvorog is made using the skimmed milk after most of the fat is extracted to make butter, so it's like 1% fat and 10% protein. Cottage cheese keeps the fat content.
You can 'fix' tvorog to be more like cottage cheese by boiling it with fresh milk, it will remove much of the sourness and add back fat content.
Saving arbitrary metadata is the exact use case for
pickle
module, you just put it together with your numpy array into a tuple. jpeg format has support for storing metadata, but they are an afterthought like .mp3 tags, half of applications do not support them.I can imagine multichannel jpeg to be used in photo editing software, so you can effortlessly create false-color plots of your infrared data, maybe even apply a beauty filter to your Eagle Nebula microwave scans.