Order of operations on image

[Eggles]

Currently I am having to process a large number of images taken with a digital camera. The images download on to the computer as 72dpi JPGs, on which I must perform a number of 'operations'. These include cropping, making a clipping path, resizing (downwards), resampling, and converting to CMYK TIFs.

Is there a correct sequence I should do these in? I am doing them in the order listed above i.e. after cropping and making my clipping path (with the Pen Tool), I then resize. Since the images come in many times larger than I neeed the final image to be, resizing increases resolution to a value usually above which I need (300dpi). So I then resample to get the resolution down. At some point I also convert the mode to CMYK. Then finally save as a TIF. Am I doing this in the correct order? or doesn't it really matter?

Any advice gratefully received.

 

[Manic]

it shouldn't realy matter but as preference I eould use the following order.

change to CMYK
resize
re-sample

Then the croping and clipping.

I usualy do any resizing early on as it can take a lot of time out of later operations on an image.

but it is usualy down to personal preference.

hope this helps Manic
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I've broken it again !!
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lee.gale@virgin.net

 

[blueark]

There's usually no real difference in the order, not for the operations you describe. Some operations (certain filters for example) will have different effects depending on whether they're applied before or after resampling.

Speaking of which, what do you mean by resizing THEN resampling? You can do this with one operation. That should save you some time! And yes, this operation is usually done first to save time on subsequent operations (it's obviously quicker to convert a small image to CMYK than a large one).

You should also look at setting up actions for any repetitive sequence. For example, if you're reducing each image by a set value, record an action to do this and maybe convert to CMYK. It may be helpful to run a batch process for this action for all your images before opening them individually to take care of cropping and clipping paths.

 

[Eggles]

blueark

Firstly, all the images are different, and need to be cropped and resized by quite variable amounts - it is certainly not constant. I resize first then resample, so that I retain the optimum number of pixels - the amount of cropping required for each photo varies, but the final size has to be consistent in that the smaller dimension (doesn't matter whether it's width or height) is equal to a certain length. Once I have the size right, I then can set the resolution to 300dpi. I was taught to NOT do the two operations in one step (although I know it is possible). Apart from which, I am not in a hurry to do these, so would rather get them right.

As for recording actions - I have absolutely no idea how to do this, plus since each photo is different, in terms of the cropping required and the resizing/resampling necessary, I don't see that it would be possible, even if I knew how to do it.

The two responses above seem to be in in direct conflict as to when it is best to convert to CMYK - the former suggests it be done before resizing, the latter says after. The file sizes I am dealing with are not huge and I don't really think this operation is particularly time-consuming, so it probably doesn't really matter anyway.

Whether there is a correct way of carrying out the steps I need to do seems debatable, so I think I'll keep going the way I have been - the final result looks OK.

 

[blueark]

I'm assuming from your original post that by both resizing and resampling you're referring to 'Image Size' operations rather than a cropping operation (whether it be with the crop tool or Canvas Size operation). That being the case it makes no difference if you do them at the same time. In fact, here's an even quicker way to do it... look at the options for the crop tool. You can enter the finished dimensions and resolution directly and cut out a few steps at once!

Actions are useful for 'dumb' operations, which as you point out would not be the case for most of what you need to do. Converting to CMYK is probably the only thing, but if you have many images, it may still be worth considering: just open a sample image, open the actions palette and create a new action, convert to CMYK and stop the action. Now under File > Automate > Batch... you can apply the action to a whole folder of images which gives you one less thing to worry about. I like to let my computer do repetetive things like that because (a) I can and (b) sitting back with a nice cold beer is far more enjoyable!

As for when to convert to CMYK, I would stand by what I said, but if the images are small, the difference would be negligable so it's really down to personal preference. Most of the work I do is for commercial printing, so the images are quite big and the time difference can be quite noticable.

I sympathise with you wishing to do things right -- I tend to get into strange time-consuming habits too until I realise that there usually is a quicker way to get exactly the same results. These forums are great for that sort of information, so I hope you try out a few of the suggestions and see what works for you.

 

[Eggles]

Re: I'm assuming from your original post that by both resizing and resampling you're referring to 'Image Size' operations...

Yes.

Re: ...look at the options for the crop tool. You can enter the finished dimensions and resolution directly and cut out a few steps at once!

I have never noticed this - will check tomorrow.

OK - I am going to try and set up an action for converting to CMYK, as this is about the only thing that is consistent with all images.

Thank you for all your suggestions.