title: Identify nonselectable image from PDF
body: <p>I need to identify (but not extract) nonselectable image from PDF. I went through the thread '<a href="https://stackoverflow.com/questions/2693820/extract-images-from-pdf-without-resampling-in-python">Extract images from PDF without resampling, in python?</a>' but didn't get a solution. If I'm correct, PyMuPDF can only identify the selectable images (when you click it the image gets shade). Please refer to the line chart in 61899345.pdf in the <a href="https://www.dropbox.com/sh/21lu3y8ph3a58z2/AAC-J18zmQv2ZF6TWJy2hUfua?dl=0" rel="nofollow noreferrer">link</a> as an example of nonselectable image. Because I have a large number of such files to process, I guess I have to find a rule to define an image. Thank you.</p>