How do I retain quality of images for PDF and reduce file size?

[patrickq]

Hi,

Hoping someone can help with this and that this is the best forum to ask question.

I am creating an ebook with about 60 screenshots in it and need to find a way to make it a manageable size when a PDF.

I'm running an older Mac, with Tiger OSX.4.11 and don't have Photoshop etc, I use an older free Image Well program to reduce file sizes etc. I am creating the ebook in Pages and then exporting from there as a PDF.

The images start off as about 1MB+ TIFF files. I have tried reducing the image quality down to jpegs of about 25kb and then saving the whole document using the Print/ColorSync/Reduce File Size method, but still have a 3.6MB PDF and the image quality is not good.

Any suggestions of the best way to tackle this? I'm not in a position to be able to redo the screenshots, so will have to work with the existing TIFF (or in some cases JPEG) files.

My first desire is to be able to have a crisp screenshot, rather than a somewhat fuzzy blur, is there any clever technique to do this while also reducing the file size?

Thanks ... and Happy New Year

Patrick

 

[Flynnstone]

Have you tried PNG format?

 

[MisterMe]

Hi,

Hoping someone can help with this and that this is the best forum to ask question.

I am creating an ebook with about 60 screenshots in it and need to find a way to make it a manageable size when a PDF.

I'm running an older Mac, with Tiger OSX.4.11 and don't have Photoshop etc, I use an older free Image Well program to reduce file sizes etc. I am creating the ebook in Pages and then exporting from there as a PDF.

The images start off as about 1MB+ TIFF files. I have tried reducing the image quality down to jpegs of about 25kb and then saving the whole document using the Print/ColorSync/Reduce File Size method, but still have a 3.6MB PDF and the image quality is not good.

...

Are you using MacOS X's built-in print-to-PDF facility to generate your PDFs? If you are, then you should get serious with your work. You need Adobe Acrobat Pro--in particular, Adobe Distiller. Distiller is the professional application for generating PDFs. It provides numerous options for handling raster graphic images within PDF files.

 

[Jim Campbell]

My first desire is to be able to have a crisp screenshot, rather than a somewhat fuzzy blur, is there any clever technique to do this while also reducing the file size?

The short answer is: no. Over 60 images and your complaint is that your PDF is "still" 3.6Mb? I fear your expectations may be unreasonable.

If you're not interested in print (if you're creating an ebook, that would suggest you're not) then I'd consider using JPEGs rather than TIFFs, which may yield a saving in filesize. Simply cropping your screenshots down to show only the exact part of the screen you're trying to illustrate will also help, if you haven't already thought of that.

I created this PDF as a beginner's guide to doing what I do for a living, which runs to 40 pages, 160 screen captures and weighs in at ~6Mb, which I think is pretty reasonable. This was created in Pages and exported to PDF via the print function in OSX.*

Cheers

Jim

*For the simple reason that I was able to copy a series forum posts straight out of Safari; paste them into a Pages document, and have Pages respect the text formatting, but retain the image placement and even scale the images to the right size for the new document's double-column format.

 

[patrickq]

Thanks for the quick replies, especially at this time of year.

My post was not very clear, my excuse is it was past midnight then and bed was beckoning.

I have been reducing the original TIFFs to jpgs and wasn't so worried about having an end size PDF of maybe 5-10 MB, but was surprised that even when I reduced the jpg size of images to about 25kb each (so total for images was 1.5MB) that the PDF was 3.5MB, with about 10,000 words of text and a 200kb header (I assume this doesn't multiply by the number of pages!). I exported to PDF using the Print function and Reduce File Size.

I tried using PNG and GIF but JPEG seemed to give the best file size/quality combination.

Unfortunately at the moment I can't buy any software, so Adobe is definitely not in the equation.

Jim, thanks for the PDF, it helps a lot to see the example of your book. I have gone close up where I can, but several of the screenshots are of the whole browser page, as I have to highlight parts spread over the page. I have been using Preview/Grab to get my screenshots (cropping at this stage, rather than later), is this what you use?

I'll go back and have a go at some sort of compromise size, I was hoping that I was missing something obvious that would give me superb quality images at 10kb each

Patrick

 

[Jim Campbell]

I have been using Preview/Grab to get my screenshots (cropping at this stage, rather than later), is this what you use?

Sorry for the slow reply, Patrick…

I use CMD-SHIFT-4 for screen caps, since this lets you grab a portion of the screen with click-hold-drag, or individual palettes or menus with SPACE.

I use GraphicConvertor to eliminate the alpha channels from the PNGs and then save as JPEGs, since GC seems to yield smaller JPEGs than just about any other software package I've used.

Cheers!

Jim

 

[patrickq]

Jim, thanks for reply, no worries about delay, I've been laid up with flu for over a week and been nowhere near the computer until today.

I've never used Graphic Converter, hadn't realised there was so much in it. I'm not hugely skilled (as you may have gathered) with all Mac software etc, I'm not sure exactly how you use or individual palettes or menus with SPACE, don't see how I do this.

When I use CMD-SHIFT-4 and get a PNG, which I open with GC, it doesn't have Alpha Channels, only the option to add them (and then remove them), what are the Alpha channels in any case? When saving to JPEG, do you just use the standard settings?

I took a sample screenshot, PNG file size 164KB. When saving this to JPEG it suggests size will be 147KB, but when I save the size is 240KB. If I reduce the quality, it still produces much larger JPEG size than suggested. I guess I'm missing the obvious ... again! Thanks for your patience and quite understand if you get bored with this

Patrick

 

[MisterMe]

... I guess I'm missing the obvious ... again! Thanks for your patience and quite understand if you get bored with this

Patrick

Q: How do I get to Carnegie Hall?
A: Practice!

People can give you pointers, but they can't give you proficiency. If you don't know how to do this stuff, then you need to learn just like everyone else. Play around it. GraphicConverter does an excellent job of giving you the file size for each particular set of settings. Only experience can teach you how to optimize your image for the file size and output quality that you want.

Practice!

 

[Jim Campbell]

Jim, thanks for reply, no worries about delay, I've been laid up with flu for over a week and been nowhere near the computer until today.

I've never used Graphic Converter, hadn't realised there was so much in it. I'm not hugely skilled (as you may have gathered) with all Mac software etc, I'm not sure exactly how you use or individual palettes or menus with SPACE, don't see how I do this.

When I use CMD-SHIFT-4 and get a PNG, which I open with GC, it doesn't have Alpha Channels, only the option to add them (and then remove them), what are the Alpha channels in any case? When saving to JPEG, do you just use the standard settings?

I took a sample screenshot, PNG file size 164KB. When saving this to JPEG it suggests size will be 147KB, but when I save the size is 240KB. If I reduce the quality, it still produces much larger JPEG size than suggested. I guess I'm missing the obvious ... again! Thanks for your patience and quite understand if you get bored with this

Patrick

If you've captured a menu or a floating palette using CMD-SHIFT-4 then space, then the PNG will have an alpha channel. If you're just dragging a marquee, then it won't. JPEGs can't contain alpha channels (which are used for transparency effects, like the soft drop shadow on OSX dialogue boxes) so you need to go Picture -> Alpha Channel -> Flatten Alpha Channel to get rid of it if you have one.

Save As … Format JPEG. Tick the 'Web Ready' and 'Merge Color Profile' options. The PDF I linked to before used 75% image quality for the screen grabs, which knocks the file size down a good whack without making the image too mushy. You wouldn't want to print them, but for screen viewing they seem to be OK…

Cheers!

Jim

 

[patrickq]

Jim,

You're a star, thanks for explanation, making sense to me at last. Just done a trial run through and all easy, even for me You can relax now

Patrick

 

[designguy79]

... and a 200kb header (I assume this doesn't multiply by the number of pages!).

I think this is your main problem. Have you experimented with leaving your header on just 1 page and erasing from the rest? Of course, I could be mistaken, too. I wasn't sure how to google a question like that..