pdfsandwich: pdfsandwich (add OCR text layer to scanned PDF files) pdfsandwich: pdfsandwich: pdfsandwich generates "sandwich" OCR PDF files, i.e. PDF files which pdfsandwich: contain only images (no text) will be processed by optical character pdfsandwich: recognition (OCR) and the text will be added to each page invisibly pdfsandwich: "behind" the images. pdfsandwich: pdfsandwich: pdfsandwich: pdfsandwich: pdfsandwich: