CPI ImagePrep short review

by Donald Jenner

What vector-based clipart brought to user-oriented computer graphics tools in the '80s, will be enhanced by bitmap art in the '90s.  More able, less costly hardware will combine with easy-to-use software to make real-world and computer-generated, true-color images readily available both to professional graphics artists and the broad range of everyday graphics users.

The ease-of-use factor is entirely a matter of better software.  A case in point is Computer Presentations, Inc.'s family of bitmap image processing software, ColorLab (incorporating scanner control features) and ImagePrep (image management and adjustment features without scanner-control).

Both ColorLab and ImagePrep are Windows 3.0 products.  They take full advantage of that environment's memory management and display capabilities.  Both install easily; both share a similar intuitive interface.  Both handle a wide variety of image formats and management features.

ImagePrep displays the basics of bitmap handling common to both programs.  It reads the major bitmap formats -- Targa, .PCX, Microsoft's new .BMP (both Windows and PM versions), Aldus TIFF and Compuserve's .GIF (useful especially with Autodesk's animation products) as well as proprietary Computer Presentations format.  True-color (24-bit) images are displayed as such if a Windows-supporting display system is present (if not, ImagePrep does the best it can with the hardware available).  To cover cases where the image is in a strange format, ImagePrep can grab the image from the screen of another Windows application.

Most important in the file-handling area, ImagePrep can compress bitmaps written to its own proprietary format.  This squeezing can reduce file sizes by as much as a factor of 10, without noticable loss of quality.  Since bitmaps can be enormous (a true-color, 300 dot-per-inch scan can easily run to 24 megabytes), the ability to squeeze them for archive purposes is not merely a frill.

Image processing is supported in two categories.  Basic image processing covers changing a file from color to grey-scale (with or without dithering) or black-and-white.  This is a check-off-the-box menu option; the image can then be saved under another name.  One nice touch:  ImagePrep has a couple layers which prevent accidentally overwriting a file; the original version is always protected.

The same pull-down processing menu offers control for dithering applied to color images.  When changing an image from 24-bit true-color to a more managable 8-bit (256 color) image, the program can optimize colors without dithering, or can apply different algorithms to get the most effective image.  These can be tried onscreen, and even saved (under different names) to check for quality and effect (and most especially, conflicts with other schemes that may be used along the line, resulting in impaired output).

Color images can be enhanced with a series of simple controls available from the Enhance pulldown menu.  These controls overlap to some extent, so the best possible combination of changes can be selected and tested onscreen.  Brightness and contrast are controlled by simple "slide-bar" controls, with a readout indicating the extent to which the alteration will take place.  The same sort of control is availbable for RGB color.  Color balance uses a meter metaphor to simplify balancing a color image based on a neutral tone.  Click on the meter button and the cursor becomes a crosshair with a small circular window; move it over the neutral shade to be used for setting the balance (a larger picture of the area is displayed in the "button") and click on the mouse.  The color balance sliders are set; they can be modified at will, or the automated adjustment accepted by clicking on OK in the dialogue box.

Gamma (color tone) correction is equally automatic.  The default curve can be automatically set to display, or modified, for each of the basic colors (red, green, blue and gray) or any one or group by selecting the appropriate check-box.  The curve can be adjusted in a universal manner, or upper and lower ends of the curve can be independently fine-tuned.

In short, ImagePrep provides the kinds of image processing for real-world pictures in computers that a photo lab affords for photographs.  ColorLab, the company's scanning software, has all these features, and adds a module to control the scanning process.

ColorLab uses the window-in-window capability of Windows 3.0 to open a second window onscreen.  This window displays a representation of the scanner bed, with optional rulers to allow for precise control.  The area to be prescanned or scanned is controlled with a marquee having the usual handles at corners and sides for adjustment.  Scanning and prescanning can each be set for color, grey-scale or monochrome (the latter has the advantage of making much smaller temporary files when prescanning).  Both resolution and number of colors can be set from dialogue boxes.  We tested the newest version of the scanning software with Epson's ES-300C color scanner, which can scan up to 600 dots per inch -- producing very fine, even true color pictures.  ColorLab matched the full range of this scanner's superior capabilities.  With this combination, we were able to produce real-world images for use in the most demanding illustration applications.

At first, the absence of a paint utility, along the lines of CPI's competitor program, seemed likely to be disconcerting.  However, we found that it was actually less trouble to use ImagePrep or ColorLab for most of the work.  Most of the time, the adjustments we wanted could be accomplished using the enhancement capabilities without moving to a paint program.  Where we did want paint -- to touch up a picture, or change a background, for example -- we found the process of exporting to .BMP or .PCX format for use with even a simple paint program like Windows PaintBrush was more expeditious than using the often troublesome paint program included in the competing package.

The images that resulted worked well with all the major Windows graphics applications we use.  All of them -- Micrografx Designer, Corel Draw and CSC's Arts & Letters Editor -- handle the images neatly.  Corel Draw was particularly spectacular, with its ability to handle 24-bit color bitmaps almost as handily as it could vector objects.

This suggests a change in low-cost graphics systems:  Until recently, low-cost graphics systems were limited mostly to vector-based drawing tools.  Bitmap-image handling was available, but without very costly add-ons, was not very rewarding.  On both input and output sides, that is changing as this is being written.

For example, a number of companies have introduced true-color display systems for use with standard PC-family platforms.  Raster Ops has had their product available for about a year, and Hercules will introduce its true-color board by the beginning of 1991.  This new family of display processors combines a graphics coprocessor with sufficient memory to show images up to 1024 x 768 pixels resolution in 24-bit true color -- effectively, more colors than the eye can perceive.  This kind of ability used to require a separate, floor-standing box, with a substantial 5-figure pricetag. The RasterOps system comes in around $3,000, and the there has been speculation Hercules's board will have an entry-level price of just over $1,000.  Workhorse 8-bit color systems (displaying 256 colors) are also dropping; a recent announcement offers a Texas Instruments 34010 coprocessor-equipped board for under $500. The result is a picture on the screen that more nearly approximates to what the final output will be.

Color scanning is also more affordable and easier to use.  The Epson scanner is a good example; it offers all the features of its competitors, and has set a price for it that makes it as easy a buy as grey-scale scanners.  "Why be limited?" is the message Epson is sending.  Similar messages are being sent by other scanner makers; Sharp has brought down the price of its comparable flatbed scanner, for example.  And just around the corner, the companies that brought grey-scale handscanners to market are about ready to release color versions to compete with Sharp's HandyScanner.  These units will do most of what a full-size scanner will do, without the large footprint.

Add to this the increasing availability of CD-ROM and read/write laserdisk peripheral systems, which afford lots of space for memory-hungry bitmaps.  The result is the potential for libraries of real-world images matching (or exceeding) the enormous libraries of vector clipart that have made graphics accessible to a larger audience, and easier for professional users.  Software such as ImagePrep and ColorLab is the perfect utility to go with this development.

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