Using Photoshop with Images Created by a Confocal System

Abstract

Many pure colors and grayscales tones that result from confocal imaging are not reproducible to output devices, such as printing presses, laptop projectors, and laser jet printers. Part of the difficulty in predicting the colors and tones that will reproduce lies in both the computer display, and in the display of unreproducible colors chosen for fluorophores. The use of a grayscale display for confocal channels and a LUT display to show saturated (clipped) tonal values aids visualization in the former instance and image integrity in the latter. Computer monitors used for post-processing in order to conform the image to the output device can be placed in darkened rooms, and the gamma for the display can be set to create darker shadow regions, and to control the display of color. These conditions aid in visualization of images so that blacks are set to grayer values that are more amenable to faithful reproduction. Preferences can be set in Photoshop for consistent display of colors, along with other settings to optimize use of memory. The Info window is opened so that tonal information can be shown via readouts. Images that are saved as indexed color are converted to grayscale or RGB Color, 16-bit is converted to 8-bit when desired, and colorized images from confocal software is returned to grayscale and re-colorized according to presented methods so that reproducible colors are made. Images may also be sharpened and noise may be reduced, or more than one image layered to show colocalization according to specific methods. Images are then converted to CMYK (Cyan, Magenta, Yellow and Black) for consequent assignment of pigment percentages for printing presses. Changes to single images and multiple images from image stacks are automated for efficient and consistent image processing changes. Some additional changes are done to those images destined for 3D visualization to better separate regions of interest from background. Files are returned to image stacks, saved and then printed to best reveal colors, contrast, details and features.