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General Category => General Discussion => Topic started by: njee20 on October 10, 2019, 12:11:34 PM

Title: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 12:11:34 PM
I'm in the process of trying to transfer some graphics to someone to print and it's proving markedly harder than it should!

The background is a vector graphic image, onto which I've drawn data labels (using PowerPoint) in fonts as small as 1pt which won't print on my cheap desktop printer (do they print on any home printers?), hence wanting to use a 3rd party. They're white text on a black background FWIW.

However... when I save as a PDF (the supplier's desired format) there is significant compression of the image, which means they end up looking rubbish! Grouping all the items and saving as a PNG/BMP/JPG also result in compression.

I send the PPTX file, but also had to provide the fonts I used, the supplier didn't have PowerPoint, but said in Open Office it just didn't work properly, clearly something lost in translation.

Ideally I'd like to merge the image to a single layer and save at a suitably high quality (everything is legible in PowerPoint at 400% zoom). If I have to put everything back into a graphics editor, or another software package to do this that's ok. I used Vectr to draw the graphics, but that doesn't have the (non-standard) fonts I needed. But a graphics program which allows font installation, or to use the native library, could be ok!

Worst case I'll have to strip out the text from the data labels I think, but I'd sooner not do that, as you just end up with black squares, which will look a bit daft, as they're a prominent part of the livery.

These wagons, to give a bit of context!

(https://photos.smugmug.com/2014-collection/2014-Julys-photos/i-jRHJkGP/0/b76b5a41/M/140704-024%20%20biomass%20hopper%2080%2070%200698%20118-2-M.jpg)
Title: Re: Image Compression (or not) when sending files
Post by: PaulCheffus on October 10, 2019, 12:39:29 PM
Quote from: njee20 on October 10, 2019, 12:11:34 PM
However... when I save as a PDF (the supplier's desired format) there is significant compression of the image, which means they end up looking rubbish! Grouping all the items and saving as a PNG/BMP/JPG also result in compression.

Hi

I don't think PowerPoint is the best tool for this and you really need a vector drawing package.

I did my artwork in CorelDraw, exported it as a PDF and I don't remember it compressing the image. Don't forget to convert text to curves then you don't require any of the font files.

Cheers

Paul
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 02:02:43 PM
Any free packages  :-[

Ultimately though that shouldn't matter - the loss occurs when compressing to PDF. I've seen lossless PDF creators, but no idea if they work. The worst item is a graphic anyway, which just ends up a pixellated mess.

Interesting about saving as curves within CorelDraw though, that could make a big difference.
Title: Re: Image Compression (or not) when sending files
Post by: PaulCheffus on October 10, 2019, 02:41:37 PM
Hi

Unfortunately I don't know of any free packages.

My version of CorelDraw is from around 1997 and will only run on my old XP Laptop.

What happens if you create the text in Word and export as a PDF?

Cheers

Paul
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 03:24:02 PM
Mmm, actually that's looking significantly better then it was, and I'm not totally sure why. Annoyingly Acrobat still changes the fonts though, and embedding fonts isn't possibly on the free version. Why are these things never simple!?
Title: Re: Image Compression (or not) when sending files
Post by: red_death on October 10, 2019, 03:46:00 PM
What are you using to create the PDF? The inbuilt functions of Powerpoint (depends on version) or Acrobat/alternative? There's normally a menu that you can specify any or no compression levels or set the DPI of the images.

Cheers Mike
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 04:42:04 PM
Just the inbuilt "save as", I'd not thought of a third party converter. That's a good shout!
Title: Re: Image Compression (or not) when sending files
Post by: red_death on October 10, 2019, 05:34:08 PM
I knew there was an option somewhere:

Click File > Options.
In the Options box, click Advanced.
Under Image Size and Quality, select the Do not compress images in file check box (or pick 300dpi).
Title: Re: Image Compression (or not) when sending files
Post by: Pjlons83 on October 10, 2019, 07:06:19 PM
Try printing the PDF at a big size like A3 or A1. Then when you zoom in you see that it's sharper.
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 09:06:23 PM
Quote from: red_death on October 10, 2019, 05:34:08 PM
I knew there was an option somewhere:

Click File > Options.
In the Options box, click Advanced.
Under Image Size and Quality, select the Do not compress images in file check box (or pick 300dpi).

Ooo, thanks Mike, I'll have to check that.

Quote from: Pjlons83 on October 10, 2019, 07:06:19 PM
Try printing the PDF at a big size like A3 or A1. Then when you zoom in you see that it's sharper.

Problem is that it's not an image. I could increase all the font sizes, save it as an image and then resize, but I'm not sure that would help.
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 10:23:26 PM
That's much better, thanks Mike. Weirdly the overhead warning flashes still get distorted, but everything else looks much better, may just need the printer to overlay the overhead flashes again, but that's easy enough.

Apparently the gradients are very awkward to print, so this could be a waste of time anyway! :doh:
Title: Re: Image Compression (or not) when sending files
Post by: Pjlons83 on October 10, 2019, 11:12:18 PM
Quote from: njee20 on October 10, 2019, 09:06:23 PM

Problem is that it's not an image. I could increase all the font sizes, save it as an image and then resize, but I'm not sure that would help.

Glad you got it sorted. Just for reference, we used to supply drawings to the customer in PDF format. We got a few complaints that they were distorted. Printing at a larger PDF "paper size" made it much sharper. No need to alter anything, just the paper size in the print set up. For some reason it was much sharper and you could zoom in on screen too without it blurring.

I'm not the best with IT but I can definitely say that this worked for us.
Title: Re: Image Compression (or not) when sending files
Post by: njee20 on October 10, 2019, 11:25:36 PM
Yep that would definitely work for an image, but it's not an image I'm struggling with, it's text. So I could seize the text, save as an image and then resize, but that'll almost certainly result in a loss of fidelity of the text.

The issue was that the font size was so small the PDF was becoming pixelated, now resolved (and the two fonts embedded) with Mike's suggestion, so think I'm potentially over that hurdle!
Title: Re: Image Compression (or not) when sending files
Post by: NGS-PO on October 11, 2019, 08:23:45 AM
Quote from: njee20 on October 10, 2019, 02:02:43 PM
Any free packages  :-[

Ultimately though that shouldn't matter - the loss occurs when compressing to PDF. I've seen lossless PDF creators, but no idea if they work. The worst item is a graphic anyway, which just ends up a pixellated mess.

Interesting about saving as curves within CorelDraw though, that could make a big difference.

Inkscape is a reasonably powerful, free, vector graphics program - https://inkscape.org/

Best

Scott