The color settings panel, available as a tabbed dialog box through the Retouch Image window panel tab header, is utilized to adjust the hue, saturation, intensity, and color balance of digital images captured with the DXM 1200 camera system.

Figure 1 illustrates a series of digital images that have been retouched using the color settings panel. The specimen is a thin section of pine tree tissue infected with blister rust fungus that has been stained with a quadruple mixture containing safranin O, fast green, crystal violet, and orange G. Specimens stained with this mixture respond differently, primarily as a function of the nuclear to cytoplasmic ratio, the amount of cellulose present in the tissue, and the starch and acidophilic cytoplasm content of the individual cells. The pine tree stained specimen, when color corrected, should appear bright red with deep purple midtones.

The microscope illumination was adjusted to present slight color variations when photographing the specimen in order to capture images in need of rehabilitation. Figure 1(a) presents the stained pine tree section as it was acquired by the DXM 1200 camera system attached to a Nikon Eclipse E600 microscope with the tungsten-halide lamp operating at about 6.5 volts. This condition usually results in images that have colors shifted to longer wavelengths and an overall yellowish cast. The image in Figure 1(a) has yellow color tones and appears to be slightly underexposed. Increasing the image intensity with the Color settings panel Intensity slider produces a brighter image (Figure 1(b)), but also increases the yellow overtones. Prior to making the color balance adjustment, the overall image saturation is increased with the Saturation slider (Figure 1(c)), which produces a shift in color tones towards orange. Finally, the sliders in the Color Balance menu are utilized to correct the color to reflect how the image appears in the microscope (Figure 1(d)).

Another example of color balance adjustment with the ACT-1 Retouch Image software is presented in Figure 2. The specimen in this case is a stained thin section of buttercup mature root. As acquired through the microscope operating with brightfield illumination, this specimen also produces a digital image that has an overall yellow cast, but with adequate color saturation and brightness (Figure 2(a)). The remedy is relatively simple in this case, and only a small adjustment of the color balance from yellow to blue is required to correct the image (Figure 2(b)).

The dramatic improvement in image quality produced by the Color settings panel (Figures 1 and 2) is evident by comparing Figure 1(a) with Figure 1(d) and Figure 2(a) with Figure 2(b). After the each adjustment is made to the digital image, the Apply button is clicked to administer that change to the image stored in the ACT-1 software window. If several adjustments are made (for example, color saturation and balance) that collectively appear unsatisfactory, click on the Reset button located at the bottom of the settings panel to cancel all of the correction factors made to the image.

The Color settings panel contains two groups of three sliders, one set for hue, saturation, and intensity, and the other for color balance of the complementary primary colors. Changes to hue, saturation, and intensity can be performed either by translocating the sliders with a mouse, or by directly typing the values into a text box positioned by each slider. The color balance sliders increase the intensity of the primary subtractive colors (cyan, magenta, and yellow) when pushed to the left, and of the primary additive colors (red, green, and blue) when pushed to the right. The full range of all sliders in the Color settings panel is quite broad, so care should be taken not to make excessive color corrections with this software utility.

	Interactive Java Tutorial
Retouch Image Window Explore the various features available in the DXM 1200 ACT-1 image correction and retouching software. Included are algorithms for brightness, contrast, color correction, cropping, and resizing images.

When the image meets approval, click on the OK button located at the bottom of the Retouch Image window to apply the changes and return to the ACT-1 software window. The image should then be saved with a different name by the Save As command line from the File main menu. If one of the correction factors is changed and the user switches to another settings panel, the Retouch Image dialog box (not illustrated) appears to question whether or not to apply the update. Clicking on the OK button will apply the changes, while clicking on the Cancel button in this dialog box will cancel the latest corrections. Note that clicking on the Apply button in any Retouch Image settings panel will apply the changes and reset the correction factors back to zero.

Although the ACT-1 control software Retouch Image feature is not as fully developed as high-end image editors such as Adobe Photoshop, the correction features in the settings panels can be utilized to significantly improve digital images captured by the DXM 1200. The presence of these utilities will allow microscopists to perform quick edits to digital images prior to saving the images, which can then be imported into more advanced image editors for closer scrutiny.