Image Size

[Rex]

What ho one and all,

I'm working on some tiff images, the originals being NEF files. They are saved as approx. 5000 x 3400 pixels (A3) and the file size is listed as 99.6mb. That is usually how I like things.

But these images take forever to load, and even longer to save. I don't know why, until I looked at the files size on the lower left of PS (I'm using CS3) and it says, 99.6m / 686m.

Bridge also reports a 686 file size. There are no layers and image size is correct, even reporting 99.6.

So how has this file become so large? How do I get it back to 99.6. See the attachment for details.

Grateful for any advice. Toodle pip and thanks,

Rex

[John Wheeler]

Re: Image Size

Hi Rex - If you have but one Layer here are more things to consider
- In preferences are you recording the history of your edits and storing in metadata
- Do you have alpha masks in your Channels panel
- Though they don't take up much room the Paths panel also uses memory

Not sure these are you issue yet thought it was worth mentioning.

[Rex]

Re: Image Size

Thanks for the reply.

Didn't think about whatever is being stored in the metadata. To the best of my knowledge, I am not storing the edit history but will check. It certainly does appear that the recorded file size (and based upon the speed of opening, actual file size) includes a number of layers, which do not appear when the file is opened.

Now that I think back, I was working with some layers, but I rarely save with layers. I seem to recall that I flattened the image, then saved but had some sort of 'PS is about to crash memory issue' message.

But PS did not crash and the image did flatten on the next attempt. Then I saved it (more specifically, the hourglass appeared.) But further editing was no possible. So closed the image, PS and Bridge and restarted. Everything is fine, but these few images are reporting the large size, although Image/Image size does say 99.6m.

I still have the RAW so can go back and rework.

[Rex]

Re: Image Size

I have solved the mystery. I have been trying a small program from a photography blogger that creates a number of luminosity channels. Can slelct any one and use that to create a mask for whatever purpose one want to improve the image.

Although I had flattened the image, all the alpha channels were still in place. Having deleted them, the file is now the correct size.

Rex

[klev]

Re: Image Size

I have solved the mystery. I have been trying a small program from a photography blogger that creates a number of luminosity channels. Can slelct any one and use that to create a mask for whatever purpose one want to improve the image.

It's possible to do that to some degree, but you will find it hits a wall on many things if you are trying to fully isolate a portion of the image. It's actually an area of active research due to the number of areas where this kind of computation shows up.

[John Wheeler]

Re: Image Size

I have solved the mystery. I have been trying a small program from a photography blogger that creates a number of luminosity channels. Can slelct any one and use that to create a mask for whatever purpose one want to improve the image.
Rex

Glad you found the issue Rex. Alpha Channels/Masks (as Adobe refers to them) do not get deleted with flattening (among other things). Second bullet of my last post.

When you do a Save As and specify TIFF format, it gives the options of saving Layers and Alpha channels independently (grayed out if you don't have Layers/Alpha Channels respectively). If you uncheck Alpha channels then all of those Luminosity Masks would not be saved with the file. Just a faster way to get rid of them. FYI

[Rex]

Re: Image Size

Gentlemen,

Thanks for the replies. Although Luminosity Masks are not complex as a basic principle, I seem to have a mental block as to how to use them.

This little action is very good, but it is a bummer that they are difficult to delete. There is another action to delete them, but for whatever reasons, it refuses to run.

Personally, I find Cnt click on the RGB channel the easiest way to get a Luminosity Mask.

Will look into Save As next time.

Again, thanks

Rex

[klev]

Re: Image Size

Gentlemen,

Thanks for the replies. Although Luminosity Masks are not complex as a basic principle, I seem to have a mental block as to how to use them.

Use them however you like. Here is what you're computing (r+g+b)/(3*256) at each point. Don't try to read too far into this. These are all non-linear. You are just looking for something that works. If you try to rationalize it, you're going to confuse yourself. The mechanics are not entirely intuitive.

This little action is very good, but it is a bummer that they are difficult to delete. There is another action to delete them, but for whatever reasons, it refuses to run.

it's either a bug in the action or you renamed them in a way that conflicts with the way the action identifies them. I haven't personally looked at it.

Personally, I find Cnt click on the RGB channel the easiest way to get a Luminosity Mask.

If you're creating one from that, it's basically identical to duplicating that channel as an alpha channel. The marching ants graphic just identifies borders between areas that will be greater than and less than 50% opacity in the resulting alpha.

[Rex]

Re: Image Size

"it's either a bug in the action or you renamed them in a way that conflicts with the way the action identifies them. I haven't personally looked at it."

If I really keen, I could record my own delete action.

[John Wheeler]

Re: Image Size

I believe after flattening, to delete all remaining alpha channels automatically requires a script. That has been done by others and here is a link for reference:

http://www.retouchpro.com/forums/photo-retouching/29494-way-delete-all-alpha-channels-once.html

FYI

[Rex]

Re: Image Size

John Wheeler,

Thanks for the link; very useful. It does work as it should, but seems very slow. Should it be 'sort of' instant? On a couple of occasions, it has been so slow that I could have deleted alpha channel individually faster.

[John Wheeler]

Re: Image Size

Not sure about speed of scripts.
Fastest way in my mind is through the Save As approach I already mentioned.
At least your mystery is solved on why the file was larger.

[Rex]

Re: Image Size

Just tried that for the first time and it works a treat. Many thanks.

[John Wheeler]

Re: Image Size

You're welcome Rex.