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Re: [OM] Image resolution

Subject: Re: [OM] Image resolution
From: Moose <olymoose@xxxxxxxxx>
Date: Thu, 19 May 2016 14:29:27 -0700
On 5/19/2016 3:54 AM, bj@xxxxxxxxxxxxxxx wrote:
. . .

Lower down it shows the FastStone assessment of file quality as a percentage -
usually lower than 100 !

You have completely, absolutely misunderstood. This dialog box is showing you the choice you are making between retaining detail in the file you are about to save, or saving a smaller file. It is making no assessment of the image you are saving before you save. Nor is it making a useful assessment of how much that choice will affect the appearance of the new saved image. it's just telling you how much you are going to compress the image. There are images that are hardly noticeably affected at all by quite low settings and others that are strongly affected even by high settings. FS has no way to assess these things.

You are also given options. Click on OPTIONS
and you can reduce the file size using a slider AND if you give it a
little time it will tell you the new file 'quality %' assessment along
with the size of the chosen new file. When you are happy with your
choice (which you can reverse and go back at this point in time), you
can save in the previously chosen location.

Yikes! It's still a setting you are making, not an "assessment" being offered to you. This should be obvious from the 100% samples shown in the "Options" box. They are to allow one to judge how the selected compression affects the details in the saved image.* Select an image with lots of fine detail and watch what happens as you move the Quality (compression) slider back and forth. If you computer is slow, it may take a moment or two for the change to show.

Re-saving JPEGs with greater, different, or even the same compression is a BAD idea. Uncompressing an image does not recreate the original, re-compressing this imperfect copy further degrades it from the (original) original.

The classic illustration is to repeatedly save and reload an image several/many times. Depending on the compression settings and image itself, it will slowly or more quickly turn into mush.

I've never seen these dialog boxes before, as I have no interest in saving a JPEG at even greater compression. You should never see them again.

Un Compressed Moose

What if the Hokey Pokey *IS* what it's all about?

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