# bicubic smoother/sharper



## notelliot (Feb 19, 2008)

hey guys. 

i was going through old files and from some 'ancient' jpegs from my d70s. i was going to print some 13x19's but i need to know if i'm upsizing properly. i'm using photoshop cs. here's the process:

*-*open image (in this case let's say it's 3008x2000px)
*-*using the bicubic smoother, i increase the image size by roughly 20% (img is now 3610x2400px)
*-*now using the bicubic sharper, i resize to the size required (back to 3008x2000px)
*-*print?

it feels like there's a step missing. any info is good info. thanks in advance.


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## Digital Matt (Feb 19, 2008)

Why are you enlarging, and then resizing down again?  Resize the image one time, using bicubic smoother (since you are enlarging).  If you are printing at 300 dpi, the final pixel dimensions should be 3900x5700 for a 13x19.

Some people feel that making gradual steps up the desired resolution results in a cleaner image.  I have not seen any reason to do this, but that's your option.


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## notelliot (Feb 19, 2008)

that's probably what was throwing me off. i didn't understand why i would resize back to the original after making the thing larger. 
i called a friend to ask him, and that's what he said to do. 

i don't know a lot about printing.

know of anything i can read online that would help at all? i have too many questions to ask.


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## Big Mike (Feb 19, 2008)

I agree with Matt, there is no reason to go back and forth with your image size.

If anything, you might want to sharpen after you resize.


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## notelliot (Feb 19, 2008)

okay. 

so if i'm using the smoother to enlarge, what does the sharper really do? it appears that i don't need to bother with it?


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## Big Mike (Feb 19, 2008)

They way I understand it, when you enlarge, you do it 'smoother' so that you get a more natural looking image and smooth out the details that have to be made up.

Sharpening might bring back a touch of sharpness and edge detail.

It doesn't take much.  I think that I usually use something like 200% but only 0.2 or 0.3 radius.  (Unsharp Mask)


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## domromer (Feb 19, 2008)

I've heard it argued back and forth which way to do it. 

I almost alway make images smaller and I've found bicubic sharper to work better. 
This is the opposite of what a lot of books will tell you but I always have better results when I choose it over smoother.


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## notelliot (Feb 19, 2008)

domromer said:


> I've heard it argued back and forth which way to do it.
> 
> I almost alway make images smaller and I've found bicubic sharper to work better.
> This is the opposite of what a lot of books will tell you but I always have better results when I choose it over smoother.


you're making the image smaller in this case, and i'm trying to enlarge images. unless the process is the same. i've always just used a bicubic sampler to resize smaller.


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## domromer (Feb 19, 2008)

notelliot said:


> you're making the image smaller in this case, and i'm trying to enlarge images. unless the process is the same. i've always just used a bicubic sampler to resize smaller.



I also just read a good article where Scott Kelby uses bicubic sharper to make poster size prints form a 6meg file. 

Maybe I'll scan it if I have time.


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## ann (Feb 19, 2008)

which article, as i would like to point some students in that direction.


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## notelliot (Feb 19, 2008)

domromer said:


> I also just read a good article where Scott Kelby uses bicubic sharper to make poster size prints form a 6meg file.
> 
> Maybe I'll scan it if I have time.


please do. even if i could make 8mb and 20mb files cleaner at poster size. 

the only reason i regret not going to school (i guess i still could) is for photoshop. is pretty extensive to teach yourself.


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## Digital Matt (Feb 19, 2008)

notelliot said:


> please do. even if i could make 8mb and 20mb files cleaner at poster size.



The size of the file itself, in mb has nothing to do with it's quality for enlargement.  The main factors which influence enlargement are sharpness, noise/grain, and pixel dimensions (this is the true inherent resolution of the file, and what you are manipulating when you enlarge).


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## domromer (Feb 19, 2008)

It's actually in his book. p168 . All the book shops seem to have it. 

http://www.amazon.com/Photoshop-Dig...bs_sr_1?ie=UTF8&s=books&qid=1203467233&sr=8-1


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## domromer (Feb 19, 2008)

forgive the crappy scans.


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## dkf10425 (Feb 19, 2008)

This is just my opinion but photoshop does a terrible job resampling images. Genuine Fractals is pretty much the industry standard for upsizing. It's a good investment.


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