Image quality and file size

[jh1023]

I'm working on a sort of user's guide/brochure with a lot of images. The images were originally PDFs, edited in Photoshop and saved as JPEG. I placed them in my document, and when I export to PDF they look great, but the file size is quite large. I've been trying to find a way to significantly reduce the file size without sacrificing quality. The images contain text which must be clearly legible in the end result.

So far I've tried exporting with different PDF profiles, and am getting file sizes from 15.7 MB (PDF/X-1a) to 19.6 MB (High Quality Print), or small files with poor quality images (Smallest File Size- 2.6MB). The images are all 300 ppi, and any sort of compression seems to cause a problem when viewing the PDF at various levels of zoom. This will mostly be viewed on-screen, so I'm not worried about it being print quality, but I would like the images to be clear whether they are at 100% or are viewing more of/all of the page.

Is there any way to get this level of quality in a smaller (optimistically below 5MB) file size?

 

[spamjim]

The images were originally PDFs, edited in Photoshop and saved as JPEG.

The images contain text

Do you mean single spot ink text without halftoning? If so, they should have never been opened and converted to JPG in Photoshop. Your problem to address may be higher up in the workflow.

 

[jh1023]

I'm sorry, I'm not sure what you mean by "single spot ink text without halftoning."

Would saving them in a different format be preferable?

 

[spamjim]

If you were to print the PDF file before it is altered in Photoshop, would the text likely print on a single plate, such as black? Is this regular copy text or is it graphic text?

PDF files, unless they were created in Photoshop, are not well suited to be edited in Photoshop.

 

[jh1023]

The original PDF files were definitely not created in Photoshop, they are reports generated by my company's software. The document is intended to provide examples and explanations of the available reports. Photoshop came into the picture because I needed to edit them for size as well as security/privacy.

 

[Nocandu]

Hi

Can you place the images into Indesign in the PDF format instead of converting them to JPGs?

I'm not sure how that would effect the size but it's worth a shot.

I'm not sure how Indesign handles PDF files sizes when they are re-saved in a smaller size as part of a new document.

Mike

 

[JRSroufe]

Definitely save as a PDF format. JPG compression is going to cause digital clutter at that file size regardless.