HSC's Live Picture features state-of-the-art technologies for enabling high-end image editing on the Power Mac
Trevor Marshall
My first contact with Live Picture was in June 1993 during the Digital World trade show. A rumor was circulating that Kai Krause (author of Kai's Power Tools, and HSC Software's chief technical visionary) was secretly showing a radically different image-editing program. Jerry Pournelle and I found Kai in a darkened suite that was packed with people and equipment, waxing long and hard about an early version of a new package from France called Live Picture. Using acronyms such as FITS (Functional Interpolating Transform System) and IVUE (for Image VUE, a French-language acronym), Kai tried to convince us that conventional pixel editors like Adobe Photoshop and Corel Paint would soon be relegated to the tec
hnological scrap heap.
Well, it has taken some time, but Live Picture is now shipping, and the current version is radically different from the one Jerry and I saw in 1993. No longer does HSC Software intend it to replace Photoshop, which you will need for some tasks.
However, Live Picture makes fast image editing more affordable than it has ever been before. At $3995, Live Picture is only a fraction of the cost of high-end workstation products from Quantel and Scitex.
Live Picture has already received wide acclaim, so I'll focus on just what you can expect from the newer, native Power Macintosh version. My test setup consisted of a Power Mac 8100/80 CD equipped with 40 MB of RAM (8 MB more than required), an NEC MultiSync 5FG monitor, and a FARGO Primera PRO Dye Sublimation color printer. The Power Mac's internal video was set to 832- by 624-pixel resolution.
IVUE and FITS
Live Picture's key features have as much to do with the user interface as with imagin
g technology, but because it is not possible to understand how the program works without first taking a look at the IVUE image format, we shall, in fact, do just that.
Computerized images are typically scanned, transported, and stored in a pixel-mapped format (most commonly TIFF). And, while the images on a high-resolution video monitor can become quite large (e.g., my 832- by 624- by 24-bit monitor displays 2 MB of uncompressed data), an image that is being prepared for printing can be many times larger. An 8.5- by 11-inch page printed at 300 dots per inch would end up as a 25-MB image file. Normal image editors (Photoshop and Corel Paint) scan files of this size every time they refresh the screen display.
In practice, however, most of the pixels that are read from the file are discarded, and only a few are painted through to the screen. This technique is called subsampling. But when you apply an effect, such as the unsharp mask, every pixel in the main image file must be updated. Thus, much of
an electronic artist's time is spent waiting for files to be processed.
Contrast the Collage software from Specular International (Amherst, MA), which lets the artist manipulate a proxy of the original image to speed up the operation of many page-composition (or compositing) functions. You form the proxy by sub-sampling the main image before you begin the Collage session. Then you perform all the compositing on the proxy image, which contains only a fraction of the number of pixels in the original. At the end of the editing session, Collage carries out the same functions, at full resolution, on the original. Due to the smaller number of pixels being manipulated, it is much faster to compose a page with Collage than with a pixel-based editor. On the other hand, it is useless to use high levels of zoom on a Collage proxy, which is inherently low resolution.
Live Picture uses two new technologies that effectively speed up the editing session without requiring any significant compromise in the abil
ity to zoom in to fine image detail. The first is FITS. As does Collage, Live Picture stores any changes to the image as mathematical equations. But FITS uses new ways of representing these image changes. You are not constrained merely to making compositing functions but have available many operations that are new to personal computers.
Although the changes you make affect the image on your screen, nothing happens to the main database until you finish the session and activate the FITS RIP, the raster-image processing program that converts the file for output on a raster-based device. This shifts the waiting to the RIP post-processor, which can work as a background task that you activate at the end of the day or during a coffee break. Unlike the old methods, RIP post-processing should not affect your creativity or your productivity.
Zooming In
The other new technology behind Live Picture is called IVUE, an image-storage format designed by FITS Imaging (Paris, France) to pro
vide editing software with fast access to any portion of the main image at any zoom level. The IVUE file format contains the original high-resolution image and a series of reduced resolution subimages (thumbnails). The number of subimages depends on the size of the main image; the larger the image, the more subimages are produced during the conversion process. The smallest subimage is usually around 256 by 256 pixels. When an application requests pixel data, Live Picture determines which portion of each subimage to access.
Obviously, an IVUE file will be larger than the uncompressed TIFF version of the same image--around 33 percent larger, according to FITS Imaging. On the other hand, the TIFF format supports lossless compression, and the average TIFF file takes up much less disk space when stored in the compressed form. FITS Imaging offers a JPEG compression mode, but you can expect an IVUE database to eat up more of your disk than the TIFF database of the same images. This is a small price to pay for
the increase in speed obtained using IVUE-aware applications, such as Live Picture.
An IVUE file is larger than the corresponding TIFF file because it contains several sets of images. But, because an IVUE file is structured like an indexed database, the program can display any part of any image onto the screen, at any zoom level, very quickly. Live Picture generates the screen display by interpolating between the appropriate IVUE thumbnails. At some levels of zoom, you can see the monitor first display a coarse version of the image, with the fine details painted later. But you have to be observant; on my Power Macintosh's internal video, both the coarse and detailed images were finished in just 1 or 2 seconds.
The two screens (
Live Picture 1
and
Live Picture 2
) show a concept that Kai Krause used at the 1993 meeting to demonstrate IVUE's high resolution. They show the technology's potential and its shortcomings. The screen Live Picture 2 was created
by zooming in on the glint in the model's right eye, showing that the glint is in fact a complete high-resolution "reflection" of the model's head. You can also see that this zoom level is too high. The interpolation artifacts in the original scanned image are clearly visible even though the edited subimage is perfectly clear on the screen. An HSC spokesperson says that Live Picture could not introduce such interpolation effects, however.
Because high resolution is maintained at different sublevels of the main image, there is no inherent pixellation in a Live Picture image. Although I can imagine that some high-tech spy might get a kick from hiding a highly detailed secret document inside portions of an otherwise innocuous image, it is hard to imagine any practical use for Live Picture's ability to handle such a wide range of resolutions. In fact, what you see on the screen is not what you will see on the printed page (a limitation, to be sure, of other image editors as well). When printed, this reflec
tion will again become a pixellated glint. Artists don't have to worry about pixellation at the screen level, but they'll need to pay attention to the resolution in the final printing process.
Layers in Live Picture
Images are created in Live Picture by adding layers. When an image is imported, it becomes a layer. Or, you can create a layer of a particular background color. You can also make a layer transparent, opaque, or translucent.
The
layering screen
illustrates the layering concept. On the right edge of the screen is a list of layers. Starting at the top is the base image: four scrap television sets with fractured screens. Next is a layer called "4 TVs B&W"then "TV 1 Red Maters," "TV 2 Red Onion," and "TV 3 Red Pepper." The final layer, "TV 4 Red Tomato," is partly scrolled off the bottom of the display. Some of these layers have their corresponding thumbnail images opened and some do not, but each layer has a unique place in the composition on
the screen.
Starting with the four TVs, I selected the outlines of the broken screens as masks and applied transparency to the "4 TVs B&W" layer in these specific areas. Masking is a task presumably all Photoshop users have done at one time or another, but performing it on a unique layer has one big advantage: The masking can be turned on or off at will. The original image remained unchanged. I then created new layers for the images of the vegetables, resized them, and placed them behind the appropriate TV screens.
What you see on the screen is really an "object oriented" composition. To interchange, for example, the pepper and the tomato, you merely have to select those layers and drag the images into their new positions. With Live Picture, you can continue to work on any section of the image until you are satisfied.
Only after you've made all your design decisions do you activate the FITS RIP and create the output file for the new composition. Even then, the original image remains uncha
nged. The output file is created mathematically, according to the instructions programmed into the FITS file by your actions during the editing session. Such creative flexibility is absent in a conventional pixel-mapped editor, where once you have merged a new object, it is fixed into the image, and you are stuck with it. Some desktop products, including Fractal Design Painter on the Macintosh and Picture Publisher on the PC, support floating objects, but you must merge them before you save the final image.
The Fine Art of Transparency
For some time, Altamira's Composer has had a layered structure similar to Live Picture's. I have used this feature a lot, but it has a serious shortcoming: After you've applied transparency to a layer or an object, you can't easily remove or alter the transparency. But since Live Picture does not compute the pixel changes until your composition is complete, you can change transparency or any other attribute at any time.
The
transparency screen
consists of four layers: the original color image imported from the CD, and layers called "Blur the Car," "Girls Blk & Wht," and "Background." I added the "Blur the Car" layer to try to define the outline of the subjects more vividly by reducing the clarity of the other objects, namely the car. The "Girls Blk & Wht" layer started out as a monochrome version of the original image. After I added transparency in the regions around the subjects' bodies, the original color image started to peek through. Changing the transparency on the foreground subjects to 100 percent and on the background subjects to 40 percent and 60 percent, respectively, rounded out the composition. The process from start to finish took 10 minutes, most of which was spent thinking.
A Unique Air Brush
I applied transparency with the air brush, which is the most useful tool introduced by Live Picture. The air brush generates a concentrated central stream and an area of "spray" that has a r
educed effect as the distance from the center increases. I was not too careful brushing around the edges of the subjects--you can find defects if you look closely.
You can use the air brush to spray every effect in a Live Picture composition. You can air-brush paint, of course, but you can also "brush" unsharp mask, radial blur, transparency, or colorization. Every image editor needs a feature like this. It is such an obvious concept, and it makes an artist's job so much easier.
Take, for example, the unsharp mask. Artists most frequently use the unsharp mask to more clearly define the edge of an object. So why not just spray the mask around the outline, as Live Picture lets you do? It makes you wonder why computer artists have continued to put up with defining rectangular areas.
To test this feature, I imported a sports car image into Live Picture. After just three brush strokes and 30 seconds of work, I was able to distort the car's shape significantly. I applied two vertical brush stro
kes of the distort mask to the front bumper and to the middle of the rear wheel. The speed of application, or brush pressure, determined the effect's radius of action.
I could also unbrush this effect. By lightly brushing over the distorted area (with the erase function), I made the vehicle's original shape gradually reappear. Brushing reduced the distortion's intensity, eventually returning the car to its original outline. I tried the Gaussian blur effect , which also could be removed, incrementally, by brushing with the eraser. By allowing you to spray an effect into your composition and spray the erasure, FITS has added a new dimension to artistic creativity.
Safe at Any Speed
In a direct comparison with Adobe Photoshop 3.0, which also added both layering and layer transparency, the speed advantages that its IVUE technology brings to Live Picture are starkly apparent. Photoshop 3.0 uses a few tricks to speed up the way it displays layers, but its redrawing speed drops n
oticeably as you add layers. If your images are relatively small, and you have a lot of RAM in your Macintosh, then Photoshop may be a better choice than Live Picture. On the other hand, you will lose the unique creative features of Live Picture, such as the ability to air brush your effects.
Live Picture worked well on my Power Mac 8100/80--almost too well. The editor, in fact, performed much faster than I needed. Screen redraws were so fast I found the machine pacing me; it was always finished with its work before I was ready to give it another command.
Several companies supply network-based FITS RIPs, but because even complex images are RIPed on the Power Mac in just a few minutes, I expect that it will run acceptably fast on a network. I did not test Live Picture on a network, however.
Live Picture 1.5 is not just another image-editing program. It can do things that no other editing program can. While its technical underpinnings (IVUE and FITS) are certainly innovative, I'll always va
lue Live Picture for its easy-to-use special effects. The price may seem high to the amateur electronic artist, but it is a must-have for any professional.
ABOUT THE PRODUCT
Live Picture 1.5 $3995
HSC Software
6303 Carpinteria Ave.
Carpinteria CA 93013
(805) 566-6200
fax (805) 566-6385
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Live Picture's IVUE technology uses mathematical abstraction to maintain high resolutions at widely varying zoom levels.
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Here, the zoomed-in view of the model's eye reveals a clear subimage that does not maintain its sharpness when printed out.
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Varying the transparency of layers can produce interesting artistic effects. This image was created by overlaying the black-and-white photo over the otherwise identical color version, using an air brush feature to blur the car, and then increasing the transparency in front of the subjects to 100 percent.
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Like Adobe Photoshop 3.0, Live Picture lets you assemble images from multiple layers. Thumbnails of three layers appear at the right, with the base layer at the top.
Trevor Marshall is a BYTE consulting editor. He can be reached on the Internet at
trevor@yarc.com
or on BIX as tmarshall.
Lively Pictures
