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DPChallenge Forums >> Tips, Tricks, and Q&A >> Saving as a jpg again and again and again
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Showing posts 26 - 35 of 35, (reverse)
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 11/28/2005 03:22:58 PM · #26
Interesting! In theory, the information degradation should not be asymtotic, it should continue, though it's certainly possible that there's a mathematical reason it does not. Are you sure your friend used a summing schema that summed the absolute value of the deviations, not a simple sum (where positive and negative offsets can balnce out? I also wonder whether the RMS deviation continued to increase, even if the total deviation approached steady state. An interesting problem.
 11/28/2005 03:57:24 PM · #27
Originally posted by scalvert:
You can accomplish the same thing with an Unsharp Mask adjustment layer


How can I apply an USM Adjustment layer with PS CS2? I've been looking for that adjustment layer but don't know where to find it. Any ideas?
 11/28/2005 04:10:04 PM · #28
Originally posted by patrinus:
Any ideas?


Sure, that's easy... it, uh... doesn't exist. *blush* I'm pretty sure thare's an "Ignore Scalvert" button in there somewhere, though. Just apply USM as your last step or make a separate layer as Bear_music noted.
 11/28/2005 04:15:04 PM · #29
Originally posted by scalvert:
Originally posted by patrinus:
Any ideas?


Sure, that's easy... it, uh... doesn't exist. *blush* I'm pretty sure thare's an "Ignore Scalvert" button in there somewhere, though. Just apply USM as your last step or make a separate layer as Bear_music noted.


Right: Make a duplicate layer from the BG and do your USM on that. You can overcook it a little then fade the layer opacity until it works well. Not legal in basic, BTW; pixel-containing layer.

R.
 11/28/2005 04:20:18 PM · #30
Originally posted by Britannica:

I don't know about an adjustment layer, as USM can only be applied to pixel data -- but there is a way around this that I believe worked in PS 5. To do this create a new layer on top of all others and stamp it with all visible layers (Ctrl-Alt-Shift-E, or look in the help file for 'stamp visible'), the USM can then be applied to that layer and blended as desired. Granted, if you changed any of the adjustment layers that were active when it was stamped it would have to be recreated -- but the same applies to the composite file.


It's even simpler than that; all the adjustment layers are on TOP of the base layer. If you make the base layer active and duplicate it, the dupe layer will still be under all the adjustment layers. So you can USM on that and still have all your adjustment layers intact.

The USM I'm referring to using on the flattened image is the USM I apply to the resized image; typically I need to goose the 640-pixel image a fair amount to recapture both contrast and acuity compared tot he full-size image.

R.
 11/28/2005 04:56:54 PM · #31
Originally posted by Britannica:
Just curious though, why Tiff? Png is lossless and generally produces much smaller files. Disk space is cheap, but why incur a larger resourse penalty than needed?

David

Habit from many years of working with files for pre-press. TIFF can be opened/placed in nearly every program. If space were an issue, I'd just use TIFF with (lossless) LZW compression.
 11/28/2005 04:59:38 PM · #32
Originally posted by bear_music:
Originally posted by scalvert:
Originally posted by patrinus:
Any ideas?


Sure, that's easy... it, uh... doesn't exist. *blush* I'm pretty sure thare's an "Ignore Scalvert" button in there somewhere, though. Just apply USM as your last step or make a separate layer as Bear_music noted.


Right: Make a duplicate layer from the BG and do your USM on that. You can overcook it a little then fade the layer opacity until it works well. Not legal in basic, BTW; pixel-containing layer.

R.

I just find it less confusing to save the composite layer outside the edited PSD file; less chance of accidentally saving over the PSD file after some other operation like resizing.
 11/28/2005 07:09:37 PM · #33
Originally posted by scalvert:
"Ignore Scalvert" button in there somewhere


Dammit, if I weren't sharing front page with you (You are blue and im yellow) I would have already written a hack for dpc.com with all the code necessary to "Ignore Scalvert" but I would miss some really fine shots... nevermind, my button will only be on Forums ;) haha.

One question, I understand applying the USM on a Background Duplicate is illegal on basic but if some day you asked for my original file and steps to recreate it is obvious that when I told you "Applied USM" you would have to beleive me because its impossible to know if USM was applied on the Duplicate or original Layer, so the question is... is it illegal? (according to the rules I know it is) but end result is exactly the same and it is not verifiable.

Well nevermind, I have never used it, and perhaps a useless disertion from me but I have been thinking for a while that perhaps DPC should ask for the original file and the 'original' PS file as well (big cost for bandwidth)
 11/29/2005 03:10:52 AM · #34
Originally posted by Britannica:
Just curious though, why Tiff? Png is lossless and generally produces much smaller files. Disk space is cheap, but why incur a larger resourse penalty than needed?

David

Another reason is that TIFF is the best format for working losslessly with the noise-reduction software I have. I sometimes apply NR to the TIFF, re-save as another TIFF, and then apply sharpening.
 11/29/2005 11:48:45 AM · #35
As far as i have read/heard, opening and closing a jpeg is not a problem. but opening and editing and closing is a problem. the compression used effects the pixels each time you edit and save. i have heard/not read that it takes at least 12 times of this process before there is the slightest degradation of the image. Best to make a copy of the original and edit that copy. Never edit the original, keep it separate on a DVD or CD. hope this helps!
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