ALTHOUGH COMPUTERS HAVE FOUND their way into home and laboratory during the past three decades, they have only recently entered the studio. Increases in computing speed and greater sophistication of software have helped artists to restore as well as to analyze works of art [see "The Art Historian's Computer," by Lillian Schwartz, page 106]. Although nonprofessionals may not have access to the complex multispectral image-analysis equipment used by specialists, the falling cost of personal computers and image-manipulation software is bringing electronic art-restoration techniques within the reach of many amateurs.

This trend is a welcome one because most households with young members possess many original works of art but do not have the facilities for protecting them from physical decay. Indeed, typical display sites expose paintings and drawings to diverse dangers. A mixed-media work left hanging on the refrigerator, for example, may be exposed to excessive sunlight, wide swings in temperature and humidity, grease vapors, food spatters or even sibling vandalism [see illustration below]. Furthermore, few domestic artworks are created on acid-free, archival paper; this shortcoming renders them especially vulnerable to a wide range of environmental insults. Removing damage requires a range of image-manipulation techniques. First, correct the image background: yellowing and uniform deposits of dust, dirt and grease can be removed by shifting color and brightness so that the original tone returns. (You may want to obtain a fresh sample of the paper or other medium for comparison.) Wax-based pigments tend to be lightfast, but watercolors and markers fade, so their tints will need to be corrected as well. Each point in the digitized painting is represented in terms of the primary colors cyan, magenta, yellow and black (or red, green and blue), and so it is simple to calculate these values for the background colors, define a mathematical function that will map each color to its corrected value and then instruct the image-manipulation program to apply this function.

Most of the rest of the repair work-erasing stains and signs of physical damage-is simply a matter of replacing the lost colors in the affected patches with their counterparts from surrounding areas. Fortunately, most young artists do not employ a complex palette, so the choice will be limited. (Certain artists working with wax-based pigments, however, may have utilized all 64 colors.) If the damage spans the boundary between two colors, you may have to re-create the demarcation by hand; many image-manipulation programs offer "splines" and other tools for generating smooth lines. In cases where the loss is particularly extensive, restorers may also have to re-create tonal gradations or patterns.

Sculptures and installation pieces, which are also highly vulnerable, may benefit from three-dimensional rendering programs that can recover the original form. For example, humidity changes may cause parts of a pasta bas-relief to detach from their backing. Careful measurement of the glue marks, combined with finite-element models of the appropriate macaroni shapes, will permit a virtual reconstruction. (The full capabilities of such programs, however, are beyond the current discussion.)

Extensive restoration requires taking into account the artist's original intent, which may be elicited by direct consultation ("Is that a tree?") or deduced by comparison with similar works in the corpus. At this stage, you may be able to remedy not only adverse environmental impacts but also shortcomings in the available media as well: blunt-tipped markers, crayons or pencils unable to produce the fine lines that the artist intended or perhaps the absence of a particular color from the palette.

Ultimately, the reworking of such art may reveal images that a young artist may have envisioned but was unable to put into form. Obstacles to complete realization of the artistic impulse can include a lack not only of tools but also of hand-eye coordination and of technical training. All these difficulties can be remedied by the electronic restorer.

In the bottom illustration, for example, the artist did not have access to a range of earth tones and grays in making the original drawing. Because she would have used them had they been available, the work was corrected to compensate. I recognized that the bold, sweeping strokes of green were obviously meant to evoke the swaying of tall grass in an open field. To bring out this intention, I made a series of additional refinements: modifying the grass to add finer lines and more subtle shading than a felt-tip marker could produce, removing pentimenti (lines she had crossed out and replaced elsewhere) and finally altering the proportions and the composition to achieve a more realistic effect. Executing these corrections on the figure produced the scene the artist would have painted had she the proper tools, motor coordination and artistic experience.

Considerable controversy attends such restorations. Nevertheless, I believe careful study of the artist's corpus, combined with analysis of the school in whose tradition she is working-be it Impressionist, Expressionist, Hudson River, Pre-Raphaelite, Neo-Primitive or Elementary-may yield both aesthetic dividends and a deeper understanding of the many influences that shape juvenile art.

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