Effective PPI in .eps files

[Seth McGraw]

Anyone know how to extract the effective ppi info in .eps files? Photoshop.eps and Illustrator.eps files are different, so whichever you may have info on would be appreciated. I believe Illustrator generated ones are read as .pdf docs, so it may be impossible.

Thanks,

Seth

[Jongware]

Seth McGraw wrote:

[...]  I believe Illustrator generated ones are read as .pdf docs, so it may be impossible.

Nah. Well, not for that reason, at least. (AI files, now those are saved as PDF documents, with some "private information" to reconstruct the actual Illy file.)

I don't know about Photoshop EPS (open one in a text editor, I'd say), but it's possible to store several different images into a regular EPS so you can end up with more than one "effective PPI" value for a single file.

[Seth McGraw]

So will the eps file need to be flattened in order to get a single value?

[Jongware]

I don't believe "flattening" is the term you were looking for (it usually applies to transparency & friends, and transparecny is one of the many 21st century features that are not supported by EPS).

If you mean something like 'rasterizing', sure, but if you are going to rasterize everything anyway, it would certainly make more sense to save that image in a real bitmap format such as TIFF, instead of as EPS.

[Seth McGraw]

Unfortunately these are files sent in by customers. Creating a different format and replacing/relinking is not a workable scenario. We are talking several thousand pics. When they are used by a customer, we are stuck with them. We are just trying to flight check through a script that checks for many things.

[absqua]

Why not use the built-in preflight for this? It will get the effective ppi of Illustrator and Photoshop eps's.

Jeff

[Jongware]

absqua wrote:

Why not use the built-in preflight for this? It will get the effective ppi of Illustrator and Photoshop eps's.

Uh-oh. Egg on face and all of that.

I didn't get to see the effective ppi, but if I place this EPS image into InDesign

I get a preflight message 'something is wrong'. If I make the image smaller (and thus increase the ppi), the error disappears.

[absqua]

The preflight functionality is a challenge to script, but there are code samples in the CS5 (but not the CS4, if I remember right) sample scripts. It returns a multi-dimensional array of strings—in preflightProcess.aggregatedResults—that you have to parse to get ahold of what you want. Not fun, but doable.

[John Hawkinson]

In addition to Jongware's observation about multiple raster images, you can also have EPS files with no raster images at all,

and thus no effective ppi. What's the effective ppi of a 1" black square? How about a 72-pt letter A in Helvetica?

If you are restricted to particular kinds of EPS files ,you could try parsing them yourself. After all, they're just ASCII and PostScript code.

But it 's probably better to give up completely...