Jpeg quality settings

jwshaw89 · Post by **jwshaw89** » Tue Mar 19, 2013 2:27 am

When I save my covers as jpegs in PhotoShop, I select the 'baseline optimized' option with the quality set to '12 maximum'. In doing so, the files wind up around 4 - 6mb in size, which appears to be in line with other artists' covers that I download.

However, I notice that changing the setting to '10 maximum' (changing it to 9 results in 'high' rather than 'maximum' quality) reduces the size of the cover to around 2-3mb, as seen in the attachment at the bottom of this post. I saved a couple of covers using this lower setting under a new name, opened them up and zoomed in to 100%. There appears to be no difference in quality whatsoever.

Below is a portion of the same cover saved at the two different settings to show you what I mean. I made sure I saved these portions using the different settings. The cover has noise manually added.

[attachment=25106:mb1.jpg]

[attachment=25107:mb2.jpg]

The second image is saved at the lower setting.

So I suppose the question is, if I can't see any difference, is there a difference at all? Before I rake through my folders changing all the file sizes, I want to be sure on this.

It just seems odd that the file size can be cut almost in half with no discernible effects on the image quality. Maybe it only makes a difference on images that are double figures and up in terms of megabytes?

Am I completely missing something? Anyone else tried this?

Post by **JollyRoger** » Tue Mar 19, 2013 2:43 am

I always save as Baseline Optimized set at 12.

Shwaffle · Post by **Shwaffle** » Tue Mar 19, 2013 3:33 am

I can kinda notice it on the letters on the right hand side, the curves seem a bit more 'pixely'. Regardless, I think saving at 12 is a much safer bet(Although I don't understand why people don't save as .png, the quality is maintained a lot better).

Downloading and printing off a cover that looks amazing is the important part though, file size shouldn't matter.

jwshaw89 · Post by **jwshaw89** » Tue Mar 19, 2013 3:49 am

Shwaffle wrote:
QUOTE (Shwaffle @ Mar 19 2013, 04:33 AM) <{POST_SNAPBACK}>
Downloading and printing off a cover that looks amazing is the important part though, file size shouldn't matter.

Indeed, although I was thinking more for storage purposes, particularly as I have nearly 1gb of covers.

Post by **ctaulbee** » Tue Mar 19, 2013 6:33 am

What is actually in the pixel data affects how the end result will be too. Here a pretty good overview different formats and compressions with pictures for comparison.

http://www.ampsoft.net/webdesign-l/jpeg-compression.html

Shwaffle · Post by **Shwaffle** » Tue Mar 19, 2013 7:40 am

jwshaw89 wrote:
QUOTE (jwshaw89 @ Mar 18 2013, 09:49 PM) <{POST_SNAPBACK}>
Indeed, although I was thinking more for storage purposes, particularly as I have nearly 1gb of covers.

Well, honestly 1GB is nothing nowadays to be honest. If you're worried about space, I'd download a drive mapping utility and see where you should be trimming the fat. (Treesize for Windows is nice). You could also look into cloud storage to hold your covers if need be.

Nightrider · Post by **Nightrider** » Tue Mar 19, 2013 9:43 am

I always save mine as JR does, but to be honest in your examples jw I'm struggling to notice a difference between them

Post by **Kernie** » Tue Mar 19, 2013 10:20 am

I usually go "Baseline Standard" with a quality setting of 9, unless I notice some major compression issues. Those extremely minor imperfections that have been pointed out don't justify nearly double the file size and are barely noticeable by even the most trained eyes. I'm sure the HiRes server would appreciate that you're taking file size into account when saving your covers.

Anyone with a background in designing for the web should know that the first step to saving images for data transfer is to get the best quality image for the smallest file size possible. Those slight issues pointed out by Shwaffle are not enough to waste an additional 2-3 megabytes of bandwidth and storage.

And as for the PNG option... be sure to check your file sizes before considering PNG. I just did a quick test on a 2500 x 4000 pixel image, and with JPEG compression (set at 75% quality), the file was roughly 3 MB. As a PNG-24, it was nearly 15 MB! Quite a difference... especially when I struggled to notice any glaring compression artifacts.

For further clarification, here are the two examples posted by jwshaw89 converted to a looping animated GIF. See if you can spot the quality loss... all I notice is a slight shifting in the intentional noise. Regardless, this is an issue only noticeable when putting both images side by side, without the comparison, I'm sure the quality loss would be undetectable to most folks.

[attachment=25110:moneyball.gif]

My verdict? It's okay to compress your images a little. There aren't enough benefits to choosing "Maximum" quality, in my opinion.

voetzoeker · Post by **voetzoeker** » Tue Mar 19, 2013 3:57 pm

I totally agree with Kernie on this, I also save my files as baseline standard with quality 10

The only way when printing on high end printers to get better quality in letters and logo's,
is to save your cover as PDF format that includes the vector info of the logo's and fonts used

Post by **JollyRoger** » Tue Mar 19, 2013 4:47 pm

voetzoeker wrote:
QUOTE (voetzoeker @ Mar 19 2013, 05:57 PM) <{POST_SNAPBACK}>
The only way when printing on high end printers to get better quality in letters and logo's,
is to save your cover as PDF format that includes the vector info of the logo's and fonts used

.... which is what the studio designers do...

HiResCovers.net

Jpeg quality settings

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