Imported / Placed Images - MORE (You Asked for It!)

["Dov Isaacs" <isaacs@xxxxxxxxx>]

All:

Some additional issues were raised yesterday both on-list and in
some private emails to me about me postings with regards to 
screen capture images specifically and images in general.


Issue #1 - UNIX
===============

UNIX is not my specialty and Adobe no longer provides a version of
Photoshop for any flavour of UNIX. Thus, my advice for UNIX users
of FrameMaker are effectively to capture the raw image as TIFF,
process the image on Windows or Macintosh to obtain the EPS file
with the image interpolation option, and then move the resultant
EPS file back to your UNIX-based system for use with FrameMaker.


Issue #2 - File Size - Screen Captures
======================================

There is no question that the binary EPS files that result from the 
procedures I outlined yesterday are somewhat bloated compared to other
files holding the same content. The resultant PDF files at the end of 
the process, though, are exceptionally compact.

To show what is going on, I captured an image showing one of the 
PSCRIPT driver dialog windows. I saved the resultant RGB image in a 
number of different formats. The following are the files, sizes, and 
explanations:

Printer Properties.bmp - 899 KBytes

	RGB and K only, no CMYK option, no compression option,
	no display/print-time interpolation,
	limited cross-platform interoperability,
	application/driver resampling problems

Printer Properties.gif - 20 KBytes

	RGB only, no CMYK option, 24 bit color reduced to 8 bit color,
	no display/print-time interpolation,
	application/driver resampling problems

Printer Properties.tif - 61 KBytes

	no display/print-time interpolation,
	application/driver resampling problems

Printer Properties Direct ASCII.eps - 2735 KBytes

	no compression, enormous size (includes TIFF preview)

Printer Properties Direct Binary.eps - 1462 KBytes

	no compression, large size (includes TIFF preview)
	care must be taken in setting Windows PostScript printer driver
	to correct binary option (most often TBCP if not AppleTalk printer)

Clearly, you are indeed paying an on-host penalty in file size by using
the EPS approach that I outlined. The resultant PDF generated from this
content most often is SMALLER than the PDF generated from TIFF equivalents
and has higher quality, but you will pay in terms file size of the on-host
"content" files with the images.

(You may ask "why are the EPS files from Photoshop so bloated?" The answer
is two-fold. Part of the problem comes from the fact that Photoshop does
not have a compression option for non-JPEG EPS export, although it has a
ZIP compression option for non-JPEG PDF export. The other part of the
problem is the TIFF preview header, which surprising enough, takes at
least as much space as the "base" uncompressed image in PostScript. Yucck!)

But alas, I did find a way of fixing this problem enough to be quite a bit
more tolerable. (If local disk space is not a problem, then you need not
worry about trying this stuff out!)

Instead of saving the image as EPS with the interpolation option in either
Photoshop 6 or Photoshop Elements 1, save the image as Photoshop PDF with
the interpolation option and ZIP compression (not JPEG!!) using either one
of those programs. THEN, in Acrobat 5, save the PDF file as binary EPS, 
TIFF header, language level 3. (In Acrobat 4.05a, export the PDF file similarly!)

Resultant files (both ASCII and binary flavours):

Printer Properties.pdf - 23 KBytes

	Most compact format for this image type
	Not appropriate for FrameMaker import/placement.

Printer Properties from Acro5 ASCII.eps - 400 KBytes

	Slightly larger than binary equivalent,
		much larger in the general case, though
	(includes TIFF preview)

Printer Properties from Acro5 Binary.eps - 396 KBytes

	Slightly smaller than ASCII equivalent,
		much smaller in the general case, though
	(includes TIFF preview)
	care must be taken in setting Windows PostScript printer driver
	to correct binary option (most often TBCP if not AppleTalk printer)

With the replacement step of generating PDF instead of EPS
and then the extra steps of running Acrobat and saving/exporting
PDF, you save over two thirds of the disk space for the EPS files.

There is no quality loss in this process. The savings in disk space is
due to the fact that unlike non-JPEG EPS export from Photoshop/Photoshop
Elements, PDF export from the same program can ZIP compress images as
well. Screen captures do exceptionally well with non-lossy ZIP compression.
The EPS save/export from Acrobat maintains the images' ZIP compression.
The remaining "bloat" in these Acrobat-generated EPS files is the result
of Acrobat's PostScript procedures in the EPS file as well as the TIFF
header.

Bottom line is that I think the extra steps are worth it if you want to
conserve disk space. If you want to re-edit THESE EPS files in Photoshop,
unlike the EPS files directly saved from Photoshop, extreme care must be
taken in opening them to avoid weird resampling.


Issue #3 - Non-Screen Capture Images
====================================

I would still recommend EPS as a better means of importing/placing images
into FrameMaker such that resampling does not occur in the application
or driver.

Likewise, I would not recommend ever resampling any such images to a 
higher resolution. Turn on the image interpolation option and let either
Acrobat or the ultimate PostScript printing device do the hard lifting
for you. You gain nothing by carrying around the extra data which really
contains no real new data.

This is most likely contrary to what your service bureaus and printers
will tell you as gospel and what their pre-flight software will advise
you to "correct," but resampling here buys nothing at all. (If they
still don't believe you, have them contact me!)


I have revised the recommendations from yesterday based on the above ...

        - Dov

========================================================================

Based on our experience at Adobe, there is one way that easily yields 
the highest quality computer screen shots for both display and 
printing.

(1) Grab the image with whatever your favorite tool is. Under Windows, 
the easiest thing to do is Alt-PrintScrn which puts the RGB bits onto 
the pasteboard. On the Mac, Shift-Command-4 followed by CapsLock yields 
an image file.

(2a) Under Windows with Photoshop 6, create a new document. It will 
automatically be the size of the image on the pasteboard. CTRL-V will 
then paste the screen capture into that new image. Then, flatten that 
image.

(2b) Under MacOS with Photoshop 6, open the generated image file (a PICT 
file with a name of the form "Picture x" where "x" is an integer).

(3) Convert the screen shot image to CMYK or grayscale to suit your needs.
Not all service bureaus require CMYK! If you are displaying the PDF file
and printing to laser printers, CMYK buys you nothing other than potentially
a larger file.

(4) Flatten the image. Layers buy you nothing here and may cause problems
later in saving the file.

(5) Do not resize or change resolution of the image!!!!!!
(Why? Because you generally don't know at this time exactly what the
magnifications and resolutions are that you will be viewing and printing
with! In fact, zooming in and out with Acrobat or Acrobat Reader changes
those requirements on the fly. Better to simply just have the captured
data. Upsampling or downsampling at time of need to exact specifications
yields much better results than multiple such transformations!)

(6a) Re-editable by Photoshop, but "bloated" EPS file size option!
Save the image using File=>Save As using the "Photoshop EPS" option. 
In the "EPS options" screen, you should use the TIFF (8bits/pixel) 
preview option (yields an EPS file that can be used both on Mac and Windows), 
Encoding "binary" (ASCII can be twice the size and JPEG is totally inappropriate 
for screen shots). Check "PostScript color management" if you are using 
color management in your workflow. The key though is that you MUST check 
"Image Interpolation". This sets a image dictionary key that Adobe PostScript 
Level 2, Adobe PostScript 3, Acrobat, and Acrobat Reader use to do very high 
quality image interpolation and/or downsampling appropriate to the device's 
actual resolution and technology at the time the image is viewed or printed. 
(Distiller passes this key along from PostScript or EPS in a PostScript stream 
into the equivalent PDF image key!) Close Photoshop 6.

			OR

(6b) Compact EPS file size option!

	(i) Save the image using File=>Save As using the "Photoshop PDF" option.
	In the "PDF options" screen, you should use the ZIP encoding (lossless
	compression) option. The key though is that you MUST check 
	"Image Interpolation". This sets a image dictionary key that Adobe 
	PostScript Level 2, Adobe PostScript 3, Acrobat, and Acrobat Reader use
	to do very high quality image interpolation and/or downsampling 
	appropriate to the device's actual resolution and technology at the time
	the image is viewed or printed. (Distiller passes this key along from 
	PostScript or EPS in a PostScript stream into the equivalent PDF image 
	key!)

	(ii) Close Photoshop 6.

	(iii) Open the resultant PDF file in Acrobat 5 or 4.05a. Save the PDF
	file as an EPS file using the export function in Acrobat 4.05a or
	the Save As function in Acrobat 5. Set the options for binary EPS, 
	TIFF header, and language level 3.

	(iv) Close Acrobat.

(7) Import the resultant EPS file into whatever application you have 
in which you wish to include the screen print. Obviously you will only 
see the EPS preview in those applications (except for InDesign), but 
your resultant printed output (via PostScript or PostScript=>PDF) or 
display via Acrobat / Acrobat Reader will be of exceptionally high 
quality. During distillation, do not downsample any of these images. 
Downsampling of the screen shots can be avoided by having a high enough 
threshold for downsampling; 300dpi or higher will do!

Working on a budget? It turns out that you can replace Adobe Photoshop 6
with Adobe Photoshop Elements 1.0 if you do not need to convert to CMYK
and don't need any other advanced image handling. This could save you
$500 a copy if your image handling needs are more limited.

NO, as far as I know, neither JASC nor Corel PhotoPaint nor any of the 
other budget image edit programs offer the EPS export image interpolation
option, assuming they even offer the EPS format. Furthermore, none of
the nifty screen capture utilities that we know of offer either EPS or
EPS with the image interpolation option.

We know of NO better means of producing high quality printed or displayed
screen shots in an output device independent manner. Forget GIF, TIFF, BMP,
and especially JPEG. Forgetting the issue of the image interpolation feature
for the time being, use of any of these formats results in the "host"
program (such as FrameMaker or Microsoft Word, etc.) doing their own 
resizing of the image in conjunction with the PostScript drivers based on
the device resolution selected. The bottom line is that by the time 
Acrobat gets to display the image or the PostScript RIP gets the image data,
the image data will have been upsampled, downsampled, resampled, i.e.
overmangled!

Also, note that for purposes of placing other images in FrameMaker or
similar applications, EPS with the image interpolation also is the preferred
means of image placement for exactly the same reasons. In terms of image
resolution, you may choose to leave as-is and let the Distiller do the
heavy lifting, if necessary or downsample in Photoshop if the original
image is grossly over-endowed, so to speak. Remember, you cannot later
reconstruct what you downsample now.

With regards to the "resolution" that you set the Acrobat Distiller
printer to, that resolution primarily affects non-EPS image handling.
As long as you set the resolution to 600 dpi or greater, character and
vector artwork placement will be fine and not affected. You don't need
to use the resolution of the final device (in fact, don't go over
1200 dpi under Windows or you might hit a nasty bug in FrameMaker's
interface with the driver).

For distillation job options, always use "compress text and line art".
This is non-lossy compression and you gain nothing by not using it
other than a larger PDF file size.

I know that this information is very much at odds with what your service
bureaus, printers, or Kinkos will tell you, but it is authoritative and
Adobe Systems Incorporated stands behind it completely when used in
conjunction with Adobe Acrobat and RIPs with Adobe PostScript Level 2
or Adobe PostScript 3.


** To unsubscribe, send a message to majordomo@omsys.com **
** with "unsubscribe framers" (no quotes) in the body.   **