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Resize Photo Without Making Blurry

Feb 7, 2012, 01:14
Post: #1
Resize Photo Without Making Blurry
Hi,

I want to know how to resize one of my photos to 190px wide by 147px high? When I do it becomes super blurry and I need it to be crystal clear...am I correct in assuming that it has to be a landscape picture? Are there special sharpening tools that I need to use, etc.?

Thanks!
Regan
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Feb 7, 2012, 06:04
Post: #2
RE: Resize Photo Without Making Blurry
Hi there,

Thank you for your response and for your helpful advice...I am completely new to picture editing and I have no clue how to do anything, so I will probably ask for at least a billion clarifications...:-)

It does seem to make a difference when I make the landscape picture 190x147 and when I make the portrait one the same size...the portrait one comes out much more smooshed...so, I get that they will both be blurry, but I actually meant that it seems better to use the landscape to keep most of the pic in tact...

What do you mean by downscaling 2x? Do you mean if I resize the picture twice? What Gaussian blur would I use for the picture 190wide by 147 high?

I tried the unsharp mask and that did help...





(Feb 7, 2012 01:36)ofnuts Wrote:  Downscaling a picture makes it blurry. Landscape or portrait orientation is the same.

There are two things to do to mitigate the problem:

1) although it is counter- intuitive, pre-blur the picture. If you downscale 2x, use a Gaussian blur of 2px, 3px for 3x, etc... this avoids moirés and aliasing artifacts which, even if not very noticeable, are part of the blurriness.

2) after downscaling, apply some re-sharpening to restore some sharpness. The filter of choice is Filters/Enhance/Unsharp mask (which despite its name, sharpens the pictures)

But you'l never get something which is 190x147 crystal clear because people will unconsciously look it up close and see the pixels. The accepted rule in photography is that the smallest detail one can see is about 1/1800th of the picture diagonal (which is roughly one pixel for a 1500x1000 picture), and on your 190x147 picture, a pixel is 7 times bigger than the smallest detail.
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