Photos that can't be printed

[dwk1204]

I took pictures of someone who wants them placed on a CD, so they can put them on their Facebook page. Is there a way to do something to the photos, so they can be placed on Facebook, but they would not be able to take the CD some where and print out the pictures? I tried changing the resolution to thumbnail size, but then of course that's how big they were. I guess I am trying to change resolution, but not size??

Thanks in advance for any help...

 

[Dao]

Size? Do you mean the actually file size?

 

[Dwig]

There is no way to do anything to the images that prevents them from being printed but still allows them to be displayed on a web page.

You can deliver images that are sized accurately for the web page and done with a relatively high JPEG compression. This, if done properly, will produce and image that looks OK at the modest size on the web page but doesn't print well to any significant size.

The compression (often termed "Quality" in JPEG exporters) setting is a bit of a balancing act. If your image processing app doesn't provide a good preview it becomes a bit of a trial and terror process. Simply export the image at the desired size for the web page several times, once at each quality setting. Now view them in a web browser and choose the most heavily compressed (lowest quality setting) that still looks decent in the browser.

 

[KmH]

If the images are on a CD they can be printed. All you can do is control how big they can be printed.

The quality of a print is controlled by how many pixels are included per inch, ppi.

Web image quality is controlled exclusively by the pixel dimensions of the image, 2000 pixels by 1000 pixel as an example. For the web or computer display, pixels per inch (ppi) is meaningless.

If you burn images to the CD at those pixel dimensions, at 100 ppi, a print could be made that is 20 inches by 10 inches. (2000 pixels\100 ppi=20 inches)

So, keep the pixel dimensions much smaller, say 4 times smaller, 500 pixels by 250 pixels. Then they can only print at a much smaller size 5 inches by 2.5 inches at 100 ppi. If they want to print at higher quality like 200 ppi the print would be 2.5 inches by 1.25 inches. (500\200=2.5)