When inserting images into a pdf file (each image in a different page) it is quite easy to browse the images. Why when merging the same images with imagemagick (thus, creating a very large image file) is gets very slow to view the same content? Does JPG compression has something to do with this?

  • Depends how you insert them into the PDF I guess .. usually by default images are recalculated to 300dpi in PDFs – derHugo Jul 6 '17 at 5:10
  • 1
    You can't answer that generally, I'm afraid. It can depend on the used compression library, the image type, the hardware ... One aspect that may have impact is whether the image data still fits inside the CPU cache during decompression. There may be other SE sites where you meet more experts for this subject. – Philippos Jul 6 '17 at 6:08

Probably it is because in PDF files, only the contents of the current page are in memory (maybe the last or next page depending on zoom factor). In image viewers, because they assume image files are small, they load all the file into memory, so when a really big image is chosen, maybe that image is fully loaded into memory, thus causing slow processing.

  • Yes, dpi also plays a role in it. – ProgAndPlay Aug 29 '17 at 4:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.