PE2: Saving files as .pdf and .gif?

[Rich10]

In PE2, when saving a file as a .pdf, a "PDF Options" screen appears before finalizing the save.
1) If the file is being saved as a .pdf, why is there a choice on the "PDF Options" screen for .jpeg or zip?
2) What do these choices do?
3) What does checking the "Image Interpolation" box do on the "PDF Options" screen?
In PE2, when saving a file as a .gif, a screen appears before finalizing the save, giving the choices of "normal" and "interlaced."
4) What do these choices do?
Thanks.
Richard Hirschman

[Richard_Lynch]

1) If the file is being saved as a .pdf, why is there a choice on the "PDF Options" screen for .jpeg or zip?

That is an encoding method for the image information. PDF files will tend to be smaller as they use compression. ZIP will be non-lossy, JPEG lossy.

What does checking the "Image Interpolation" box do on the "PDF Options" screen?

Image Interpolation will anti-alias the printed appearance of a low-resolution image -- i.e., it is less likely to print blocky.

Normal and interlaced have to do with the appearance of a gif image on a web page. Interlaced images appear in stages.

[Rich10]

Richard,
Thanks so much for your helpful response. Also, I bought your wonderful book, "Hidden Power of Photoshop Elements 2," about 2 weeks ago, and I am working my way through it, cover to cover. What a great help it has been for a PE2 newbie like to understand the specific tools and the ideas behind the tools.
Richard Hirschman

[Rich10]

Hi Richard,
I forgot to ask you the following in my last reply. I thought .zip files are compressed files. Yet you state that if a .pdf file is stored using that choice, it will be stored as non lossy. What am I not getting here?
Thanks again.
Richard Hirschman

[Richard_Lynch]

I thought .zip files are compressed files. Yet you state that if a .pdf file is stored using that choice, it will be stored as non lossy. What am I not getting here?

In essence, not all compression causes loss. Some is just a sound means of, say, abbreviating information that can be fully restored. ZIP files compress without losing the real information -- they just encrypt it and change the format of the digital storage to make efficient use of space. These files can be fully restored. JPEG actually approximates information using a visual algorythm that removes information that is determined not to be essential. Regretfully calculating what is visually not essential doesn't always produce the best results...and the image information will be changed -- and cannot be fully restored. It may be a slight oversimplification, but these descriptions are effective enough for most purposes.

OK?

[Rich10]

Hi Richard,
Ok. Thanks again for your very helpful information and for your wonderful book.
Richard Hirschman

[Rich10]

Hi Richard,
For what it's worth as a newbie to PE2: Here is the source of confusion behind my original post. I wanted to save my images (with layers, etc.) without compression, after I worked on them in PE2. When I clicked on the "save as," menu choice, I saw the .pdf extension with the word "Photoshop," next to it in the menu list of extensions. Without thinking too much about it and not realizing this is an extension that could be used with Adobe Acrobat, I assumed it was the native Photoshop format that would save files as uncompressed. So I was then surprised to see the save as .jpg or .zip choices on the next screen as part of the save process. I now realize that I should have been saving my files with a .psd extension which, in the menu list of extensions, also has the word "Photoshop," next to it. Nevertheless your information was helpful. Sorry I didn't realize my mistake sooner.
Richard Hirschman

[Richard_Lynch]

Actually, whether you save as a PSD, PDF or TIF, I believe there will be few instances where you will actually lose information, and all files will re-open with information intact (of course that is with certain qualifications, such as not choosing JPEG compression). There is nothing wrong with the PDF choice, and actually the files ARE Photoshop native PDF files...when you open them in Acrobat Reader, for example, I believe some of the information is converted (in any case, you won't be accessing the layers). That same file in Photoshop, however, retains layers, vector information and more. Some files will be more compatible with other programs. I believe Adobe is grooming PDF as a format for broad capability, and it is probably a better format for working between Illustrator and Photoshop, for example. TIFF is a widely used graphic format accepted by many graphic and layout programs (where PDF may not be).

There is a breakdown of the file types in the Adobe documentation, I believe...You may want to look at the options.

[Rich10]

Richard,
Thanks again.
Richard Hirschman