Color Tab

The Color Tab is only used when you are processing multiple filter images into a color composite. For one-shot color images such as those from DSLRs, you should use the Auto Color Convert feature on the Select Tab. The controls on this tab are enabled only when a color group is selected in the tree control.

Stack handles several different kinds of color image composites, including:

Note that although an Individual Planes group contains subgroups from multiple channels, it does not generate a merged color result and does not enable controls on the Color Tab.

The color balance can be adjusted using the color matrix. The Input rows are multiplied by the value in the matrix and transferred into the Output color planes at the top. For simple RGB stacking, all values are zero except for Red-to-Red, Green-to-Green, and Blue-to-Blue.

If the filters are not ideally matched to human color vision, additional adjustments can be made by adding positive or negative values in the other slots. For example, the CRI Micro*Color LCD tunable filter (commonly used in laboratory imaging applications) has significant overlap between the color bands; by turning on the Use CRI conversion matrix check box, the color matrix is loaded with finely-tuned values suitable for that device.

The Defaults button will load simple 1:1:1 balance settings, or the equivalent subtractive values for CMY imaging. For recommendations on determining the correct color balance ratios, please see the Color Balance section in the Imaging with MaxIm DL chapter.

The Auto equalize background check box attempts to neutralize the color background of the image. This is done to remove the effects of sky glow, light pollution, or changing conditions during capture of the different filter bands. This is quite accurate as long as the image has significant background area, as opposed to being completely filled with nebulosity. Additional tweaking can be done using the Color Balance command after the stack is complete.

If a Luminance filter is used, you can adjust the Luminance Weight (%). 100% means that the luminance information in the RGB filters is completely replaced with the Luminance frame data. Also you can select the Conversion color space, as follows:

The choice of which method to use is a matter of personal preference. Some images may work better with one method than another.