The Digital Eclipse DXM 1200 ACT-1 control software has an Option settings panel (Figure 1) that can be utilized to configure various functions related to image capture. Among the variables controlled by the Option panel are image resolution, auto printing, automatic image enhancement, noise reduction, and color mode.

The ACT-1 control software is capable of capturing images using two resolution modes that are selectable in the Mode menu of the Photo settings control panel. High-resolution images can be acquired using the Fine mode, which features a resolution range between 12 and 0.3 million pixels. Images of lower resolution can be captured more quickly using the Quick mode that has a range between 1.3 and 0.3 million pixels. Even lower resolution images can also be acquired of selecting the resolution change ratio in the Option settings panel. By default, this option is set to the Off state with a resolution change ratio of 75 percent loaded into the menu. The feature is selected using a checkbox (see Figure 1) and is equipped with a pull-down menu to display the list of resolution reduction options.

To activate the Reduce Resolution feature, use the mouse cursor to place a check mark in the checkbox, indicating that the resolution change function is turned on. If the checkbox is clicked again, the check mark disappears, indicating that the resolution change function is again turned off. After activating the feature, use the pull-down menu to select a change ratio. The ratios available are 25 percent (highest reduction), 50 percent (medium reduction), and 75 percent (lowest reduction). For example, an image normally captured in Quick mode at a resolution of 1024 x 768 pixels would be resized to 768 x 576 pixels at 75 percent reduction, 512 x 384 pixels at 50 percent reduction, and 256 x 192 pixels at 25 percent reduction (all images are recorded at 72 pixels per inch).

The effects of resolution reduction on image quality are presented in Figure 2. A stained thin section of plant tissue was captured at a resolution of 1024 x 768 pixels utilizing the Quick mode without resolution reduction, and a small portion of the image is illustrated in Figure 2(a). Reducing the resolution by 75 percent results in an image having a pixel dimension of 768 x 576, with a corresponding slight increase in pixel size (Figure 2(b)). At 50 and 25 percent resolution reduction (Figures 2(c) and 2(d)), pixel size continues to grow as the overall image size is made smaller. The Reduce Resolution feature is a convenient tool for producing images having a reduced size that can be readily transported electronically through email or http protocol (on a Website).

The Option settings panel can also be utilized to select auto printing of digital images acquired with the ACT-1 control software. The default setting is auto printing turned off (Figure 1). To activate the auto printing feature, click on the Option settings panel tab in the main window and click on the Auto Print checkbox. The result will be a check mark appearing in the box, indicating that the auto printing function is turned on. If the checkbox is clicked again, the check mark disappears and the auto printing function is then off. When this feature is activated, digital images will be printed to the default printer immediately upon capture. Note that the auto printing function can not be turned on or off when the continuous exposure mode (time-lapse cinemicrography) is on, preventing images from being automatically printed during continuous image capture, regardless of the setting of this function.

A limited enhancement of digital images can be made automatically and immediately after acquisition by utilizing the Auto Enhancement feature in the Option settings panel. The default setting for this software routine is off. To enable the feature, choose the Option settings panel tab and use the mouse to place a check mark in the checkbox adjacent to the Auto Enhancement menu. In order to disable automatic enhancement of images, uncheck the checkbox. Digital enhancement is limited to contrast, color level, and sharpness. Adjustment of these variables can be accomplished either by using a set of up- and down-arrow buttons (see Figure 1), or directly typing the values into the text input box next to the menu item. The default value for each enhancement feature is 0 with a normalized maximum value of 15. When this feature is selected, the enhancements are made to the digital image after capture, but before storage on the computer hard drive.

A series of digital images that have been altered by the DXM 1200 ACT-1 Auto Enhancement feature are presented in Figure 3. The specimen is a stained thin section of plant tissue imaged under brightfield illumination with the DXM 1200 camera system attached to a Nikon Eclipse E600 microscope. Without any enhancement (including white balance) the image (Figure 3(a)) appears to have a slightly gray background with sufficient edge definition, contrast, and color saturation. When a contrast value increase of 5 (33 percent of the maximum) is added to the digital image (Figure 3(b)), differences between the background and the stained tissue become far more apparent, and the overall image is brighter with an increase in color saturation and edge definition. Increasing the color level to a value of 3 (200 percent increase) results in the digital image illustrated in Figure 3(c). Although color saturation and contrast are not as pronounced in Figure 3(c) as they are in Figure 3(b), the overall image brightness is greater than without any enhancement (Figure 3(a)). Finally, Figure 3(d) illustrates the same specimen with a sharpness increase of 10 (66 percent of the maximum). Edge definition is much greater in Figure 3(d) than any of the other images, but color saturation and contrast have not been significantly increased. When applied correctly, the ACT-1 Auto Enhancement features can produce a definite improvement in digital images recorded by the DXM 1200 camera system.

A choice of Color Mode for image capture can also be selected in the Option settings panel. The default setting for this feature is full-color positive images. Alternative choices are black & white and color negative images. The Color menu contains three radio buttons labeled Color, B&W, and Negative. Clicking on the appropriate radio button will enable the desired image color capture mode. Several digital images captured at various Color Mode settings are illustrated in Figure 4. The specimen is a stained thin section of pine tree stem. Presented in Figure 4(a) is a digital image of the stained tree stem captured in RGB full color mode, the default setting for the DXM 1200 ACT-1 software. Selecting the B&W option produces an image devoid of color, as illustrated in Figure 4(b). Alternatively, using the Negative option results in an image that has inverted colors that mimic a chrome (transparency) negative (Figure 4(c)).

Noise caused by long exposure times of 10 seconds or more can be reduced by activating the Noise Reduction checkbox in the Option settings panel. The default setting for this option is noise reduction turned off. In a manner similar to other settings panel features, the noise reduction function is activated and deactivated by placing a check mark in the checkbox. Figure 5 illustrates the effect of the DXM 1200 ACT-1 software noise reduction filter. Presented in this figure are two fluorescence digital images of bovine pulmonary arterial cells grown in tissue culture and stained with three fluorochromes. After fixing, the cells were imaged with an Eclipse E600 microscope utilizing a DAPI, FITC, Texas Red filter combination Nikon multiband triple filter set for a period of 45 seconds with the DXM 1200 camera system. The image on the left (Figure 5(a)) was integrated for a period of 60 seconds without the benefit of the noise reduction filter algorithm. On the right (Figure 5(b)), the image was also integrated for 60 seconds, but this time the noise reduction filter was turned on. Note the dramatic reduction in noise when the filter is applied, although there is also an accompanying softening of the image. The ACT-1 noise filter works very well for images integrated for a period ranging from 10 to 60 seconds, but for longer exposures, the lack of CCD cooling prevents the DXM 1200 from producing images lacking in significant amounts of background noise, even with the noise reduction algorithm.