Translating text embedded in technical drawings in PDF document

I am working on an urgent translation. It is a PDF file containing technical drawings with text fragments that label the different parts of the image. I uploaded the files onto SDL thinking that the program would be able to extract the text for translation but it only extracted text present in a table at the bottom of the document and not the rest of the text up in the drawing. Does anyone have a suggestion of a solution that would not involve purchasing additional software?