Resizing - workflow order? - DPChallenge Forums

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

04/21/2004 07:32:25 PM · #1

Ok, I am getting myself confuzzled on the resizing issue, and want to know the best way to to progress, in general terms.

Start with a RAW file, drag it into Photoshop CS.

I now have a file, if I look in â��Image Sizeâ�� as follows:

3072 x 2048 pix
32.51 cm x 21.67 cm (i.e. larger than A4)
240 DPI

All well and good.

Now, say I want print the photo at A4 size (or anything other than it was really) but ALSO want to change the resolution to 300 DPI. What is the better work flow:

1) Change the physical size (i.e. 32.51 cm -> whatever cm), which leaves it at 240 DPI and THEN resample to 300 DPI

2) The same but in reverse (i.e. change the DPI first)

3)Change both the size and the DPI before hitting OK and it does it in one hit.

4)None of the above, you should really â�¦â�¦

Ignore the actual sizes involved here, I am looking for a general rule.

Also â�¦ in Photoshop CS there is now the ability to use â��Bicubic smootherâ�� and â��Bicubic sharperâ�� when resizing, which apparently removes the need for the step by step interpolations.

I remember reading, but am not 100% certain, that you use the â��bicubic smootherâ�� for reducing size, and â��sharperâ�� for increasing. Can anyone confirm this, or have I got the two the wrong way round?

All advice appreciated.

Message edited by author 2004-04-21 19:33:31.

GeneralE

Canon PowerShot S3 IS

04/21/2004 10:33:19 PM · #2

Uncheck the "resample image" box and set the dimension to what you want. Let the resolution be however high as it goes -- unless you are going to be running off many copies the extra file size won't hurt. This way, you are only changing the output size but not actually throwing away data.

Otherwise, follow the above procedure, then check the "resample" box and change the resolution to the desired value.

04/22/2004 12:43:31 AM · #3

Ah ha, as easy as that, thanks General :)

Would you also suggest the same process there if I am enlarging a print ...... uncheck resample, resize to whatever DPI it ends up at and then resample?

Also, any idea though about the bicubic sharper/softer option?

Brooklyn513

Sony DSC-F505

04/22/2004 12:49:17 AM · #4

I'm not sure about the bicubic stuff, have not looked into it yet, but try resizing by 10% increments when enlarging... takes a few runs through, but you'll notice that you don't seem to lose much detail.

Change from pixels to percent and type in 110.

(edit) Don't know why this works but it does. I've seen it mentioned here (DPC) as well as on a few web sites about PS

Message edited by author 2004-04-22 00:52:01.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

04/22/2004 12:56:02 AM · #5

Yup, know the 10% incremental resize one Brooklyn, thanks :)

The bicubic sharper/soften is designed so you no longer have to do that, it does it one hit and makes just as good a job of it as the multi stage process. I think it was new in CS.

I read a huge review of it a month or two back, they concluded it was at least, if not more, accurate than the 10% sample method.

I can't now find the flipping article though and can't remember which option worked best to reduce and which to enlarge.

I think I recall that making smaller was "smoother" as I remember thinking "odd, as when I resize in increments the last thing I usually do is sharpen".

GeneralE

Canon PowerShot S3 IS

04/22/2004 01:00:37 AM · #6

From what I've heard, it is OK to use the new algorithms in the CS version to do one-step resampling ... I haven't played with it myself.

Yes, you can use the same steps to resample larger. You can also do everything in one step by setting a fixed size and resolution combination in the Crop Tool Options; e.g. set it to 8x10 inches @ 300 dpi and whatever rectangle you mark out on the photo will be made that size; it should use the current resampling algorithm as set in the Image Size dialog, but I haven't actually used the CS version yet, so I'm projecting forward from older versions.

HRoxas

Canon EF 24-70mm f/2.8L USM

04/22/2004 01:07:14 AM · #7

Quoted entirely from the book "Adobe Photoshop CS for Photographers" by Martin Evening:

Image Interpolation

Photoshop CS provides two new interpolation options that will produce better results when you increase or decrease the number of pixels in an image. Bicubic Smoother will produce smoother results when enlarging an image and Bicubic Sharper will preserve more detail when you reduce an image in size. These interpolation methods will produce results as good as if not better than using what was known as the 'step interpolation' method and more quickly too.

04/22/2004 01:19:17 AM · #8

Thanks again General :)

Perfect there Bruchen, and that is exactly the passage I had read previously, I just couldn't for the life of me remember which way round it was. Thanks :)

By the way Bruchen, if you have it .... is that book a goodie?

Message edited by author 2004-04-22 01:20:27.

HRoxas

Canon EF 24-70mm f/2.8L USM

04/22/2004 01:33:35 AM · #9

Very good book, imo.

A friend of mine has the one for PS 7 and he swears by it. The CS edition just came off the press not too long ago.