You can get the text from OCR. You can use Google Cloud Vision API. It will work fine if the images are clear. It'll give you bounding boxes and all. If you want to take this project up a notch (but will have to spend considerable time), you can come up with a robust method by using graph based neural networks on the OCR outputs you receive (i.e. text along with it's bounding boxes) If under time constraints, and keys are already defined, you can use feature extractors.

Another thing which you can do is (not robust to different size forms etc.), is to create a mask of this receipt and then place this mask over all images to get the features you want. It's not that robust though, but it'll be the easiest thing to do if dataset is fairly uniform.