# Jagged edges due to resizing



## Nelarius (Aug 8, 2008)

I'm having troubles with downsizing. Clearly-defined, diagonal lines always seem to become slightly jagged and this is further enhanced when you sharpen the image, like in the following example.







I've tried the different resizing algorithms that Picture Window Pro offers, and tried resizing in Gimp but they all yielded similar results.

Is there any solution to this?


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## Flash Harry (Aug 8, 2008)

depends on how large the original image is, genuine fractals is supposedly the best upsizing program, but if the original is rather small then upsizing by any significant amount will produce "jaggies"


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## Nelarius (Aug 8, 2008)

I should have been clearer: I get this problem when downsizing.


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## Flash Harry (Aug 8, 2008)

Try viewing the image at 100%, if the jaggies disappear there is no problem, personally I downsize gradually, also applying USM at each stage which I limit to 40% at a time, (chopping pixels), if this is to use for web once at 72dpi-ppi I then reduce by cm till I have the size/kb required and final USM before upload.


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## Garbz (Aug 8, 2008)

I think you're still missing the point. Look at the image above. That is now viewed at 100% right? The lines are jaggy.

Unfortunately this becomes a juggling act between what can be displayed (the number of pixels you are working with) and how sharp you want the picture. The picture above does have a jagged diagonal but that isn't unexpected since there is only 1 megapixel to render it. It does become a case of selecting the best resizing window filter for the job. A lot of them (Like Photoshop's default Bicubic sharp) prioritise sharpness and this is the result.

So either increase the pixel dimensions (lots of people have large screens these days so a vertical height of over 700pixels isn't likely to annoy too many people) or sacrifice the sharpness by using a softer resizing filter or applying some blur filter to soften the edges by 1 pixel.


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## Pugs (Aug 8, 2008)

Nelarius said:


> I'm having troubles with downsizing. Clearly-defined, diagonal lines always seem to become slightly jagged and this is further enhanced when you sharpen the image, like in the following example.
> 
> 
> 
> ...


 
I find that I have this issue when re-sizing .JPG files, but not with raw, .TIF, or .PSD files.  I don't know for sure if it has to do with the information that's lost in the .JPG compression, but that's what I've always chalked it up to.


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## Nelarius (Aug 9, 2008)

Thanks for your replies! I guess I'm gonna have to play around with the image.


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