Image resizing

[agriffiths]

Hi everyone, I appologise if this topic has been covered before but I just wanted to find out which method everyone uses to resize their pics for forum viewing?

I use the image size function in Photoshop CS2 selecting a width of 750 pixels (for landscape orientation) and resample the image with 'Bicubic Sharper' (.jpg).

I'm often disapointed with the loss of quality (when viewed at 100%) using this method and I'd be keen to try some alternatives.... if there are any good ones out there! Obviously I would like to keep the file sizes to a minimum for those using dial up.

[owen]

I just do the same thing but just use bicubic. I think most if not all of the options you will need to apply some sharpening to the image afterwards to get it looking its best.

Cheers,
Owen.

[xerubus]

i just use bicubic... do all of my sharpening and pp work prior to resizing. made a simple action to resize to 600 on the longest edge.

cheers

[shutterbug]

Make sure you give it abit of USM.

[Aussie Dave]

Bicubic Smoother is best used for when upsizing your image to a larger pixel dimension.

Bicubic Sharpen is best used when downsizing (ie. for the web etc...). These are basically "auto-saves" for those that cannot be bothered to sharpen the image themselves and are happy for Photoshop to make the adjustments.

Bicubic should be used when you want to resize but take care of the sharpening/softening yourself using your own sharpening technique, or with something like "smart-sharpen".

You might find THIS interesting reading....

[HappyFotographer]

Dave

I usually sharpen prior to the resizing and then resize if I need to put them up on the web....using bicubic. I have only recently read that smoother is for for up and sharper is if you are going down.

My question then, if I sharpen the image prior to sizing just as part of my normal workflow, then decide later to resize cause I want to put it up on the web or some other use....should I sharpen again?

OR, should I not sharpen in the first place until I decide what to use the image for and sharpen only after resizing?

Have I confused you yet?

[Aussie Dave]

Dave

I usually sharpen prior to the resizing and then resize if I need to put them up on the web....using bicubic. I have only recently read that smoother is for for up and sharper is if you are going down.

My question then, if I sharpen the image prior to sizing just as part of my normal workflow, then decide later to resize cause I want to put it up on the web or some other use....should I sharpen again?

OR, should I not sharpen in the first place until I decide what to use the image for and sharpen only after resizing?

Have I confused you yet?

Interesting question. I don't think there really is a right/wrong answer for this. I guess it depends on how much you are sharpening the image, each time you do so

Some people say a very minor sharpen when first opening the image is a good thing to do, and then a final sharpen again at the very end of your process. Some say you don't need to do the minor sharpen at the start.

If you stand back and think about it, pretty much everything you do when PP'ing your image is potentially degrading the quality, so sharpening the image twice could be seen as "more" destructive than only doing it once at the end. On the other hand, what percentage of degredation are we really talking about ? I don't imagine doing a minor sharpen at the start would cause much concern (IMO). The image straight off the sensor is somewhat soft, due to CCD characteristics (I think), so the minor sharpen at the start is, "supposedly", to lift the image that little bit, prior to beginning your PP work.

As for when to do the final sharpen, if you are saving a PSD or TIFF of your NEF image, or the NEF image itself (with PP), I would PP up to the point of sharpening, then save and leave it. If you then decide to print a 16x20" or convert to 800x600 for the web, you can then use the appropriate amount of sharpening once you re-open the file (and make a copy).

I possibly do things backwards, however I usually take a copy of the NEF first up, then resize (always using bicubic), for the intended use, then do my PP work. I find that some things are best done when the image is viewed at 100%....however if you haven't resized yet, you're not looking at the real 100%. If, at a later date I decide to do another version of the same image (at a different size), I will again copy the NEF, resize accordingly and do my PP work again, which may be similar or different to the first version of the image, depending on what I'm wanting to do with it on this occassion (and also what suits the size of the image - either large print or web-sized).

I'm sure there are others that can explain their techniques and methodology (possibly better than I have done), but hopefully this gives you some ideas....

[Alex]

Dave

I usually sharpen prior to the resizing and then resize if I need to put them up on the web....using bicubic. I have only recently read that smoother is for for up and sharper is if you are going down.

My question then, if I sharpen the image prior to sizing just as part of my normal workflow, then decide later to resize cause I want to put it up on the web or some other use....should I sharpen again?

OR, should I not sharpen in the first place until I decide what to use the image for and sharpen only after resizing?

Have I confused you yet?

Dave,

Great advice on PPing workflow. I think you are spot on about saving the original NEF, making a copy with adjustments in NEF using RAW converter and then save another master TIFF file with all the PPing except for sharpening. I must firstly say that I do not use such workflow but I wish I did. All I do is don't save changes to NEF I work on then do not save as TIFF but save only the final master high res jpg that includes sharpening. Of course, if I want to make changes I will degrade the jpg and cannot undo things like USM I did on it the last time I PPed it. Recently, I had to rework an image for a client. The image had too much USM applied. Of course, I had to start from the scratch (the original NEF). This is why it is important to make all these copies, i.e. keep original NEF, NEF plus changes, and master TIFF files without USM applied - saves time and quality if you want to do something different. The down side of this workflow is the amount of disk space required - sometimes a concern with older systems (like mine).

Alex

Interesting question. I don't think there really is a right/wrong answer for this. I guess it depends on how much you are sharpening the image, each time you do so

Some people say a very minor sharpen when first opening the image is a good thing to do, and then a final sharpen again at the very end of your process. Some say you don't need to do the minor sharpen at the start.

If you stand back and think about it, pretty much everything you do when PP'ing your image is potentially degrading the quality, so sharpening the image twice could be seen as "more" destructive than only doing it once at the end. On the other hand, what percentage of degredation are we really talking about ? I don't imagine doing a minor sharpen at the start would cause much concern (IMO). The image straight off the sensor is somewhat soft, due to CCD characteristics (I think), so the minor sharpen at the start is, "supposedly", to lift the image that little bit, prior to beginning your PP work.

As for when to do the final sharpen, if you are saving a PSD or TIFF of your NEF image, or the NEF image itself (with PP), I would PP up to the point of sharpening, then save and leave it. If you then decide to print a 16x20" or convert to 800x600 for the web, you can then use the appropriate amount of sharpening once you re-open the file (and make a copy).

I possibly do things backwards, however I usually take a copy of the NEF first up, then resize (always using bicubic), for the intended use, then do my PP work. I find that some things are best done when the image is viewed at 100%....however if you haven't resized yet, you're not looking at the real 100%. If, at a later date I decide to do another version of the same image (at a different size), I will again copy the NEF, resize accordingly and do my PP work again, which may be similar or different to the first version of the image, depending on what I'm wanting to do with it on this occassion (and also what suits the size of the image - either large print or web-sized).

I'm sure there are others that can explain their techniques and methodology (possibly better than I have done), but hopefully this gives you some ideas....

[Aussie Dave]

very true Alex, the TIFF files can become quite big.

However, if you set up your layers correctly, one can use "adjustment layers" quite effectively, which is basically a seperate layer for "levels", another layer for "curves", another for "brightness/contrats" etc... Then all you need to do is turn the layers on or off (in whatever combination you want) and the image changes accordingly (and non-destructively - as you're not physically altering the "background layer"). Then you just make a copy and off you go....

There are so many tips & tricks to Photoshop....and only so many hours in the day to learn them

In regards to saving changes to my NEF files, I never save my changes to the NEF, as I don't make changes to them. I open the NEF in the Adobe Converter, choose the desired settings, then open. From here, I make a copy of the image and close the NEF (without saving). I then begin using the "copied version" by resizing, then doing the rest of the PP (including sharpening at the end), then I save to whatever format is required - usually JPEG.

Therefore, whenever I re-open an old NEF file, it is in the exact same state as it was from the camera. I'm not saying this is the best method to use, this is just my method of working.

[mudder]

Definately do all your adjustments in layers where-ever possible, leaves the orig as it was, takes much less disk space (as opposed to duplicating layers) and also enables you to go back to each adjustment type (curves, levels, sat etc) and make small adjustments to each as much as you like. I find after adjusting something like levels etc. I then go back and slightly change the curve layer etc. Using adjustment layers is an easy way to do that. Also, by using adjustment layers you can also add masks to the adjustment layers for finer control as to where and how the effect is applied too...

When originally going through your shots looking for the "keepers" I save each one as a PSD and only work on those, leaving the NEFs orig...

Using snapshots is a handy way to compare stages of your PP too...

[Alex]

very true Alex, the TIFF files can become quite big.

However, if you set up your layers correctly, one can use "adjustment layers" quite effectively, which is basically a seperate layer for "levels", another layer for "curves", another for "brightness/contrats" etc... Then all you need to do is turn the layers on or off (in whatever combination you want) and the image changes accordingly (and non-destructively - as you're not physically altering the "background layer"). Then you just make a copy and off you go....

There are so many tips & tricks to Photoshop....and only so many hours in the day to learn them

In regards to saving changes to my NEF files, I never save my changes to the NEF, as I don't make changes to them. I open the NEF in the Adobe Converter, choose the desired settings, then open. From here, I make a copy of the image and close the NEF (without saving). I then begin using the "copied version" by resizing, then doing the rest of the PP (including sharpening at the end), then I save to whatever format is required - usually JPEG.

Therefore, whenever I re-open an old NEF file, it is in the exact same state as it was from the camera. I'm not saying this is the best method to use, this is just my method of working.

Thanks for recommendations, Dave. Certainly doing every adjustment in layers pays off immensely as you can always see what was it that you did to this particular image and you can always alter it. Big file size is a price I can't afford unfortunately with my old PC, but I will save layered TIFFs when I buy a new computer.

I agree with you on Photoshop tricks - so little time to learn. Speaking of learning, I just purchased a great book on LAB colour in PS by Margulis.

Alex