Why would a bitmap be saved as EPS?

[CharlieR]

As much as possible, I like to work with files in their simplest formats. So I get curious when agencies send me images that are obviously bitmaps/scans, but they are provided as EPS files.
ie. I don't see any layers or paths.

I usually open them in Photoshop and resave as TIFF, as it has fewer options to go wrong than EPS.

Has something else been done that needs EPS format? I have noticed some of the images scale up much smoother than my TIFF version.

What benefits or situations would there be that I would want to use such an image in EPS?

Thanks

[CharlieR]

As much as possible, I like to work with files in their simplest formats. So I get curious when agencies send me images that are obviously bitmaps/scans, but they are provided as EPS files.
ie. I don't see any layers or paths.

I usually open them in Photoshop and resave as TIFF, as it has fewer options to go wrong than EPS.

Has something else been done that needs EPS format? I have noticed some of the images scale up much smoother than my TIFF version.

What benefits or situations would there be that I would want to use such an image in EPS?

Thanks

[Beth]

EPS files can also hold additional information that a normal tiff can not. For instance, EPS files have the ability to hold spot colour information (duotones, DCS files etc) that will insure proper separation in your layout ap. EPS files can also hold clipping path information that can be used to make parts of the image visable and other parts inviseable.

Yes, a normal tiff file can be saved as an eps, but there is really no need to do this. It makes the file larger (adds a low res header to it) and restricts the number of people that will be able to use/view it as those without postscript compatible printers will not be able to print eps files.

Being a big fan of the KISS principle (keep it simple, stupid). I use tiff's when ever possible. If I need to retain spot colour info etc, then I use eps.

Beth

[CharlieR]

Most of your points agree with my frustration at receiving these unnecessarily complex files.
Even the lineart b&w cartoon scans are saved as EPS.

Here's my current dilemma; on Windows platform,
I received a Mac CD (I can open Mac disks with Conversions Plus) with an EPS of a logo, words and small image of a butterfly. The client requests the registered TM symbol be replaced by an asterisk.
Opened As, EPS with Tiff preview, in Photoshop 4, all I get is a bitmap, no paths or curves, ie. nothing to edit accurately.
Imported to CorelDraw I get curves for the text, OK, and the butterfly has a curve around it.
I can then remove the TM curve and put in my asterisk.
When I export this, the weight of the word's curves is changed and the printout is too bold.

I'd like to KISS it too. Using CorelDraw is easy but it adds 2 conversions to the file, in and out.
Can this be edited in Photoshop and maintain the sharpness of the original EPS?

[Beth]

Guess I forgot to mention that eps files are metafiles and as such can contain both bitmaps and vector information in them. But
opening any file in photoshop...will rasterize what ever is in there. And hence will not be editable in conventional means (no longer vectors and type, but pixels). In your situation, you could use the erase and erase the pixels that have the TM symbol and then add the asterik with the type tool (although this kind of thing is much easier in PS 5 or 6...but can be done in PS4). You can maintain original sharpness of the image, if you take care. If this is to be just a black and white image...use the 1 bit mode and use a resolution that is appropriate for your final output device. If your rip is outputting 1200 dpi...that is what res you want the bitmap to be. 2400 may be overkill...but if there is small type...it may be just what you need to maintain the sharpness. If you have colour or greyscale info there, then you may loose sharpness of type. Res of this should be 1.5 to 2 times the output linescreen. Go the higher number for higher quality...especially when there is type there.

When opening/importing the eps in draw...be sure to select the file type as "postscript interpreted". If you do not select this and use the "all files", you will be importing the header only. But I guess you must have done this as you can select items and delete them.

As far as the printing your draw image is concerned...are you printing on a postscript device. Is it true postscript? If not, this may be the problem

Somebody who is familiar with CorelDraw may not realize this, but Adobe Illustrator and Freehand does outlines a little differently. Illustrator calles them strokes and these will end up being seperate items in the file. ie the fill will be one object and the stroke another. You will be able to see this if you ungroup an item that has an outline on it. So...if you selected the outline object and applied an outline to it in Draw...this would make the item appear bolder. Not sure if this applies...but it is an idea.

Beth

[CharlieR]

Thanks.
It's getting off Photoshop but;
I have used Illustrator in the past. (used to have a Mac too but that end of the business dried up)
I have Illustrator 8 for Windows still shrink wrapped, which I was contemplating selling.

Do you think it would be better than CorelDraw 9 at creating EPS files that 'behave' better, re: transparency, line weight, etc.? when imported to Quark 3.31?
eg. I have vector only illustrations (no bitmaps) but when I use them in Quark they appear and print with a partial white background unless my prepress service cleans it up.
From Quark's end, I don't see anything about v4.0 specs that involve changes in EPS handling.

Thanks again.

[Beth]

I dont use Draw 9 so I cant tell you about the eps quality. I have heard that it has improved. I dont know. But since I have vowed not to buy another version of Draw (until they rewrite the code), I am stuck with Draw 7. And as far as eps files are concerned, I do not really trust them. The header size is bigger than the actual postscript info in the file. And other programs can have problems with them as I sometimes have problems parsing the files in Photoshop. Draw 5 made very good eps files and I sometimes save a draw 7 file as draw 5...open in Draw 5 and export from that program as an eps. Kind of a convoluted process.

As far as Illustrator is concerned, I definately trust the eps files more than I do those from Draw. But IMHO, Illustrator is a program that needs serious improvements in the interface. Being raised on Corel Draw, node editing in Illustrator drives me nuts. You have to select a tool to draw a shape, then another tool to add a node, then another tool to move the node and another to change he node from one type to another...AARGH. Node editing in Xara or Draw 9 completely outclasses illustrator. Freehand is pretty good in this area, but not as good as Xara or Draw. But never the less, Freehand is the program that I have choosen to do my work in. At least for the time being. I do want to learn Illustrator better, as I like some of the things that it can do...but a few minutes of manipulating curves usually end up with me shutting th program down.

As far as transparency in an eps file is concerned. DONT DO IT. These special effects create phenominally complex postscript files that usually results in the RIP hanging or trashing the file with a postscript error. You are best to rasterize anything with transparency. Remember the KISS principle. A bitmap is about the simplest thing a RIP can handle. No complicated math...just dot after dot. With complicated vector information...the RIP must process each item. If you have something that is grouped, or in a blend or with lens effects to it...the RIP has to interpret everything associated with that item all at once. Postscript is very compartmentalized. Each item must be processed and then rendered. If you have a group of objects with blends and other groups of items...that to postscript is one item with one heck of alot of math describing it. And have you ever looked at the file size of your print files from Draw...wow. And when you add effects like transparency and lens effects the print files can easily blow up to 200 to 400 megs. Ouch.

Do you know how your printer guys are fixing the problem on their end? Bet ya a nickle, they are rasterizing it.

Pixelate with pride,
Beth

[Jake Freeze]

To edit nodes in Illustrator you need only select the Pen tool and use Command and Option keys to change its editing mode. [img]/infopop/emoticons/icon_wink.gif[/img]

[Beth]

Thanks Jake. That helped. Along with using the keyboard shortcuts A and P,and shift C. I still have problems selecting a node sometimes. When I go to move a node with the direct selection tool, I often end up moving the whole object instead of just the node. Using the shift key helps.

I dont want to offend illustrator users, but I do think this could be done without all the keyboard shortcuts etc. THe other things in Illustrator are very fun to use--easy to access and dont get in the way of the creative process. I love the brushes, styles and reliability of eps files.

Is there a way to duplicate/copy-paste an object without any offset. Some programs call this a power paste or paste multiple. I cant find anywhere in prefs to set this. Am I missing something.

Thanks,
Beth

[CharlieR]

Beth,
You mention not to use transparency in an EPS and that it is a special effect.
Is not an object composed of paths (my idea of true postscript) transparent by definition? ie. anything on the page outside the paths is visible?
This is a logo with complicated curves.
In CorelDraw, you'd have to combine the objects to get the effect of the background showing through.
I know by checking that the number of nodes is an issue, especially for a PS Level 1 printer.

To rasterize this means I'd have to make a bitmap version for every background colour it would be placed over.
Is that what you mean?

Regards, Charlie