On Sat, 05 Nov 2005 20:54:30 -0600, maria wrote:
Thank you all very much for your help. Let me be a little more lear. I work on 1024×768 images because I manipulate the images with Photoshop and other programs. I cannot work on them when they are at any bigger sizes. BTW, how do you guys work on huge images on your screen with Photoshop?
I don’t quite follow this. I routinely work with 12MP images. The zoom function in Photshop allows you to see part or all of the image at any time without changing the number of pixels in the image.
On a related note, for most purposes, size and PPI are irrelevant. What is important is the number of pixels in the image and the color depth. Only when you are ready to target the image for print or display does the size/PPI come into play.
Many filter and painting plug-ins
would take forever to implenet at such large sizes.
Now, back to the printing. I need to have printed images of size 28×21(lengthxheight) inches. That is a 4×3 size as the 1024×768. I can save my 1024×768 image in any format because I have it as a PSD file.
The original images were JPGs at 8 megapixels. However, I need to have printed the modified PSD images which are now 1024×768. What should I do?
You are not doing to be able to produce results that are satisfactory by most standards from this image. You started out with an 8MP image. By resizing to 1024 x 768, you ended up with a 0.75 MP image. Your best bet is to go back to the original image and start over.
Conventional wisdom is that you need 300 PPI for printing. For 28 x 21, this is about 53MP. For most purposes, though, I think coventional wisdom is wrong. I’ve seen entirely satisfactory prints at say 150 PPI. For 28 x 21, this would be about 13MP.
That is at least in the ball park of the original 8MP image. If I were starting with the original 8MP image, I would suggest 2 possible approaches.
1. The 10% upsize approach. A pretty well-know Photoshop trick is to upsize the image using "bicubic smoother" in several 10% increments until you get the size you want.
2. Use Genuine Fractals.
In either case, I’d probably up-size it to roughly 8400 x 6300 pixels for this print size. I have GF and have tried it side-by-side with the 10% method. If I look at the resulting image very carefully, I think GF is slightly better — but only slightly, and I’m not convinced it is really noticable in prints viewed at any normal distance.
All of this assumes that you go back to the original 8MP image. If so, you should be able to get a satisfactory (for most purposes) image at the size you mention. However, there is simply not enough information left in a 1024 x 768 image to print at that size, and there is nothing you can do to change that.
If you did not save your original images, you made a big mistake. You should always without fail save the unaltered images from the camera. This is your digital negative. Indeed you should make sure you have 2 copies of it before you do anything else.
(1) What should I put as a ppi for the resulting image?
(2) What is the best format to save my image in with Photoshop (TIF, Etc.)?
The short answer is that you should store your work copies (remember you still should have your unchanged original) in a lossless format — I use Photoshop’s PSD format.
(3) Would the image then be ready for the printer? I do have Genuine Fractals and Smartscale. but as most of you said/implied, I don’t really need these programs at these dimensions.
Thank you very much, again!
maria