
Editimage(Display Utils)     Khoros      Editimage(Display Utils)

     Psuedocolor

     Pseudo provides a method of altering the image's colormap.
     This tool allows the user to select single colors or ranges
     of colors from the colormap, or directly from the image, and
     alter those particular mappings. The upper portion of the
     psuedo color window contains a pallet, which is a block of
     pixel color boxes that are arranged in the order that they
     appear in the image's colormap.  The upper leftmost pixel
     box is the first color in the colormap and lower rightmost
     pixel box is the last color in the colormap.  When a range
     of colors from the pallet is chosen for altering, all colors
     that sequentially lie between those two colors in the color-
     map are also altered.

     The two larger boxes in the upper left hand corner of the
     pseudo color window are selection boxes, which show the
     first and last pixel colors of the selected color range.  If
     only one color has been selected, the two boxes will display
     the same color.

     The three color bars below the pallet contain the three
     values of the selected pixel; the values of the selected
     pixel will depend on the colorspace model which is currently
     chosen. It is these scroll bars that are used for altering
     the colormap.  For instance, if RGB is the current
     colorspace model, the scroll bars will represent the red,
     green, and blue values.  They will be labeled "R", "G", and
     "B", and will appear in red, green, and blue, respectively.

     Colorspace Models

     The Pseudo Color function may use any one of eight color
     systems available with Editimage: RGB, CMY, HSV, HSL, YIQ,
     XYZ, UVW, or GREY.  One can change the current colorspace
     model that is used with the Pseudo function by clicking on
     the desired colorspace model.  The scroll bars which
     correspond to the coordinates of the chosen color system
     will update immediately when the colorspace model is
     changed. For a detailed explanation of each colorspace
     model, see the section on "Colorspaces".

     Selecting A Range

     Single colors or ranges of colors can be selected in two
     ways for interactive colormap changes. First of all, selec-
     tion can be accomplished via the pallet by placing the mouse
     cursor on the first color in the desired range and clicking,
     and then placing it on the last color in the range and
     clicking again.  The two selection boxes in the upper left-
     hand corner show the colors that have been selected.  The
     second way of selecting a range of colors is to place the
     cursor in the image window and perform the same process as
     was described above.  The only colors that will be altered
     are those that lie between the two colors in the selection
     boxes.  Selecting a single color for colormap manipulation
     is identical to selecting a range of colors - just click
     twice while the cursor is positioned in the same position.

     Changing the Colormap

     After a color or a range of colors has been selected, the
     color map can be changed using the color bars.  To the right
     of the color bars are the three values that create the color
     shown in the leftmost selection box.
     There are four ways to change the colormap.

     1.   Click the left mouse button in a color bar.  This will
          increase the value of that color by 4 units.

     2.   Click the right mouse button in a color bar.  This will
          decrease the value of that color by 4 units.

     3.   Depress the center mouse button in a color bar and drag
          the cursor left or right, until the correct color value
          is obtained, then release the mouse button.

     4.   Place the cursor at the desired point along a color bar
          and click the center mouse button.  This will set the
          color to the value which corresponds to the cursor's
          position on the color bar.

     Undoing Changes

     To undo a color change, simply select the "Undo" button on
     the bottom of the pseudo color window and the most recent
     color change will be reversed. Color changes are kept in a
     stack, so all color changes can be reversed by repeatedly
     selecting "Undo".  Warning:  Since all colormap operations
     are tied together, "Undo" will also reverse color changes
     made using "LUT" or "Windowing/Thresholding".

     Copyright 1991, University of New Mexico. All rights
     reserved.

Khoros                    Release: 1.0                          1

