Image quality on resized images

Image scaler add-on.
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dstonek
Posts: 52
Joined: Fri Mar 21, 2008 3:19 pm

Image quality on resized images

Post by dstonek »

I cannot see differences between setting 'quality=0' or 'quality=1' in scaling.properties.
I set 0.8 by default but I see artifacts on people faces so I made some test on extreme values.
Is there something I am missing?
I am resizing from 12Mp to 500 pixels max size.
The differences between this photos and the Irfanview's (a nice program to handle images) generated ones are appreciable.
Thank you
PS: In all quality setting the jpeg file size is 35Kb Irfanview's 42Kb (80/100 qual)

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support
Posts: 1503
Joined: Sun Jan 27, 2008 6:19 pm

Re: Image quality on resized images

Post by support »

Try values from 0.05 to 1.0, you will see the differences. For 0.1, JPEG compression is good but image quality is very bad. For 1.0, quality is perfect but image size is big.

dstonek
Posts: 52
Joined: Fri Mar 21, 2008 3:19 pm

Re: Image quality on resized images

Post by dstonek »

I aaaaalways forget to clean the java cache. To do this in Firefox I have to close and open the program.
500x380 pixels takes around 174kb (this image) in quality 1
35Kb in quality 0.6
49Kb in quality 0.8

Is it possible to control sharpening amount?
I would prefer less filtering.
Thank you.

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support
Posts: 1503
Joined: Sun Jan 27, 2008 6:19 pm

Re: Image quality on resized images

Post by support »

No, this feature is not available. But it could be a good idea. Do you a have link that explain the basics of such filtering ?

dstonek
Posts: 52
Joined: Fri Mar 21, 2008 3:19 pm

Re: Image quality on resized images

Post by dstonek »

Well, I've read something about sharpening several years ago but I don't have a modern link.

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support
Posts: 1503
Joined: Sun Jan 27, 2008 6:19 pm

Re: Image quality on resized images

Post by support »

I've found this one:
http://www.photoshopsupport.com/tutoria ... ening.html

Does it fit to your definition ?

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