User Manual - pancroma

Input Channel Adjust Group Utility (Grayscale; RGB; Pan)This useful utility allows you to add intensity to either a single channel (grayscale)or to individual blue, green and red channels (rgb and pan). A common exampleis if an image has a blue or green cast or tint. By decreasing the blue channel,the level of “blueness” of the image will decrease in proportion to the slidersetting. You can also increase any or all of the channels either independently orin equal proportion (when the ‘Lock RGB Ratios’ check box is checked.Set Standard Input Channel Levels Group Utility (Grayscale; RGB; Pan)This utility is closely related to the ‘Input Channel Adjust Group’. The radiobuttons are essentially adjustment ‘presets’ that will set the input channels forforest and desert images.IMPORTANT NOTE: After selecting a preset, the individual channels can still beadjusted independently, although they cannot be saved.As an example, open a single grayscale band as in the previous section. Makesure that the ‘Activate Image Processing Routines’ check box is checked andthen select ‘Display Files’ and then ‘Display Single Grayscale Image’. Instead ofthe image being immediately generated, the Image Processing Data Input dialogbox will appear. The box is full of blank areas separated by a series of checkboxes. Check the box labeled ‘Apply Contrast Adjust’.When you do so a slider will appear on the screen. The rest of the imageprocessing utilities work similarly: they are inactive and invisible until activated bythe user. When the check boxes are activated, the user interface functionality ispresented. In this case, moving the slider to the right increase the contrast of theimage and moving it to the left decreases it. The same is true for the hazereduction function. Experiment with both of these. When a single band isloaded, the processing of course applies only to that band. When multiple bandsare loaded, the changes apply equally to all three input bands.Another useful processing utility is the ‘Input Channel Level Adjust Group’.Enabling this check box presents a single slider when a grayscale image isloaded. Moving the slider from the neutral position adds or subtracts from eachpixel value in the image. There are 256 possible values for an 8-bit pixel value,and the increase or reduction of the channel level is displayed in to the right ofthe slider. Adding or subtracting values uniformly from a single grayscale imageis not very useful, except for making the image appear lighter or darker. Its realutility is in the adjustment of RGB and PAN images. Selective reduction of theblue channel level uniformly will result in the RGB or PAN image being “lessblue” and “more red and green”. While it is possible to adjust the bands singly, itis usually easier to adjust them all at once.156