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DPChallenge Forums >> Tips, Tricks, and Q&A >> Resizing for DPC - HELP!
Showing posts 1 - 7 of 7, (reverse)
03/31/2018 01:15:46 PM · #1
I have been absent from DPC for a while, and am experiencing an epic failure in downsizing my photos to 1200 pixels @ 700pixels, and also with sharpening. I used to use a variation of the Adamus sharpening and down sizing method, and then go through the old Save for Web in photoshop to save the image at the required resolution. I could save most pf my images at between 85% and 100% quality. I have two entries in voting at the moment that are, quite frankly, embarrassing. I had to save one of them at something like 60% quality, and it shows. On my MacBook Pro it didn't look too bad, but on my PC at work it looks dreadful. I am trying to put a FS entry in, but hitting the same problem. At 100% quality, the photo is 27.1 MB at 3078 pixels square. Reducing the photo to 1200 pixels square gives me a file size of 4.7mb at 100% - and that is before I have sharpened. I am using Nik Colour effects, and Photoshop CC 2017. Any suggestions as to what I am doing wrong?
03/31/2018 01:28:12 PM · #2
Well, the more sharpening you do the larger the JPEG file will be, since sharpening adds detail. Also a square image is usually a lot larger than the normal rectangular one. I usually resize my images a bit smaller than the 1200px maximum, and I also usually try to resize in an "even" percentage to avoid calculating "fractional pixels". Try scaling your image to 33.33% (should give you an image 1025px) and see what you get.
03/31/2018 05:19:16 PM · #3
Unless you have very large areas of extremely fine detail, you should be able to squeeze it down. It's true that it may take something less than 85% quality for photos with lots of very fine detail, but the difference is normally not noticeable.
If you want another set of eyes on your potential entry, PM me, I'd be glad to take a look.
03/31/2018 07:24:56 PM · #4
My heavily-processed 1200x1200 entries frequently get me down to the 75% quality range, and occasionally even worse. It all depends on the granularity of the detail present. Don't worry about that %, just make it fit. I can't honestly say I see the difference on my own images between 100% and 75%. Maybe a TINY bit when I view them on my ultra-HD laptop screen, but most people don't have a screen like that anyway. On my 27" ViewSonic I really can't tell the difference.
03/31/2018 11:23:29 PM · #5
One other note ... digital noise counts as "detail" and can greatly increase the size of a JPEG image at any given quality setting.

If your image has significant (or noticeable) noise you might try using a noise-reduction filter or program before sharpening (which accentuates any noise present).

If/when I use N-R I try to do it on the original before any editing, as most editing (e.g. tone adjustments) can also make the noise worse, though in this particular case it might not be worth going back to the beginning if your editing was at all complex.

Oh yeah, welcome back!

Message edited by author 2018-03-31 23:24:46.
04/01/2018 01:17:28 PM · #6
This discussion sent me on a search for examples of the impact of different jpg "quality" settings on image appearance. Found one source with multiple examples that helped me get a stronger grasp of the tradeoffs. EXAMPLES. Although based on Lightroom processing (Photoshop save-for-web uses different scale), the examples might still be useful. Some images (e.g.: with broad expanses of sky) begin to show banding artifacts part way down the scale, while others (even with much fine detail) can go quite a bit further without much visual impact.
04/01/2018 05:06:03 PM · #7
Aaah. Iím not the only one! I was using advice from Snaffles that was working well but since coming back, using new PS, Iím really struggling. Pin-sharp at processing but hideous once Iíve downsized using old PS ĎSave to Webí. Any advice gratefully received!
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