Resizing and sharpening

I expect that this is a dumb question.

I like SilkyPix and would use it as my RAW converter but of course it's no good for removing dust spots or cloning for which you need something like PhotoShop - true?

So, Raw into SP, save as TIFF, load into PS, clone etc. then save and indeed if I'm posting a website - resize and save. The advice seems to be sharpen as last step and especially after resize so that impoies sharpen in PS.

It seems to me that the image will be subjected to two bouts of sharpening:

One from SP when it saves the TIFF
One from PS after resize and save as JPEG

Is this not a 'bad thing' and if so what do I do about it?

Many thanks

Mike

Sharpening in Martin Eveneing's Photoshop 7 book is given about a page, by the time the CS2 book arrived it ran to many pages, so thoughts on sharpening have moved on considerably.

I really suggest you read the appropriate sections of that book for in depth understanding.

As a starting point, when converting from the relatively soft RAW image applying some capture sharpening may be a good idea. You can allow the RAW converter to do it, or perhaps try Mattmatic's "Sharpen-o-Matic" which a search on this forum will find for you.

Any localised creative sharpening during the PS work may help the image.

The final output sharpening is the last thing done and prepares the file for the printer or other output device.

Files once opened should be saved in lossless formats such as PSD or TIFF. The exception is images destined for web use which are generally saved as JPEGs.

The simplistic approach is to do the sharpening last of all, especially if the original out of camera is a JPEG.

Don't forget though that all this assumes that the image is being used for a large high quality print. We can take the simplistic route quite happily if we are discussing web use and 6" x 4" prints.

With RAW files, it's possible for Silkypix to apply no sharpening at all, so theoretically you could do all the sharpening as a final stage with another program if you like*, or even transfer a TIFF back to Silkypix after cloning etc and sharpen and resize then.

Obviously this would be hassle and you have identified a major weakness with SP. Maybe one day SP will incorporate PhotoShop type functions so you can do everything with the one program. Or perhaps SP and PS will eventually merge altogether?

Personally, so far, I rarely do any cloning (or any sophisticated maniplulation) and I don't even own a copy of PhotoShop. For pictures with dust spots, I just deal with them in a final stage AFTER sharpening and resizing with Silkypix. I use a free program called Pixia to clone the spots out manually. I don't think anyone notices. It didn't stop me winning last week's competition anyway I'll be sticking with SP anyway as I like the results and user interface very much.

Perhaps the best compromise is to do the main (initial) sharpening with SP, make a full size TIFF from SP with no USM sharpening, open with Photoshop or whatever, do your cloning, etc, then finally apply USM and resize.

* This would loose the benefit of using Silkypix's arguably superior sharpening algorithms, and you wont be able to view the image properly to work on it in SP.

That is not the most simple or convenient approach with Silkypix. With Silkypix it's actually easier to apply what you call the "capture sharpening" than not, and it lets you view the image more clearly as you work on it. SP works differently from other programs in that you don't have to wait to apply sharpening (or anything else) for best results as it automatically re-does all the processes for you in the optimum order.

As mentioned already the best approach to image sharpening now seems to be the incremental method.

I apply a small amount of "capture sharpening" during Raw conversion & then some for output - I actually use "photokit sharpener" plugin for Photoshop which I find very effective

simon

The best method I have come across:

Open the image in photoshop
Now I work with my photos at larger than 6mp from my K100D, actually 11mp. I dont know why, I scale them down anyway, but this gives me a width of 4000px

At 4000px, duplicate layer (ctrl+J), apply high pass filter at 0.3-0.5px, set layer to overlay.
Resize to 3500px, repeat steps
Resize to 3000px, " "
Etc, every 500px, down to 1000, then resize to 800 and do a final highpass.

If you just want to sharpen for printing, I recommend either using this method down to the size you want, or using your RAW converter's, but dont overdo it.

I'm wondering what the logic is in continually resizing as every time you do that you are resampling and therefore reducing the image quality.

:

Well you guys have done me proud with plenty of advice to consider.

Given I like the Silkypix capture sharpening and the easy control it gives over the basic settings I think I'll probably:

Take the SP capture sharpening
Apply any cropping
Hope that I can complete all post processing in SP
If I need to resize for web etc. then do this in SP as well

If I need to save as TIFF and remove dust marks and cloning in Photoshop or similar
Then use PS facilities thereafter for resize, save, sharpen

But I really do appreciate the time and effort you have put into helping me and I hope I don't seem to be ignoring good advice (then again if I am I fully expect you'll tell me!)

Mike

Left side is resized from 4000px to 800px and sharpened using highpass on 0.5 and overlayed.
Right side uses the repitition.

Id say it preserves detail, but maybe its a personal opinion?
It all depends how you like your sharpness

Here's the same picture, but with a little USM applied to the left hand side only. There's not a huge amount of difference to my eyes, just a bit coarser, perhaps I overdid it a bit...




I do resize in stages, but I halve the dimensions each time, and use USM. Will try it with the high pass filter though.

Why do you upsize your pics to 11Mb though??

Dan

If I'm honest,
I have absolutely no idea

I use the RAW converter in photoshop, and its just set to open at 11mp.

And using the USM, I think, yeah its not really noticable, the left is just as sharp but by resizing and sharpening the details in stages, I think the right has retained more detail.

All this is very difficult to assess on a forum image, but the differences of different methods do become very important when printing to A3 or larger.

Photoshop resampling is now so good that resampling in stages (although that was usually done when upsizing) is no longer necessary. In fact, it's debateable whether programs such as Genuine Fractals are needed either.

Bicubic Smoother will very effectively upsize in one step.

Bicubic Sharper will maintain sharpness for web application when downsizing.

Bicubic (the only option with PS7) is also very effective anyway, but the newer options are better.