A very useful feature in FX-Net is the Color Map Editor.  Using this, you may edit any image loaded in the primary window.  You can be very creative with the colors you choose to use, but it takes a bit of experimenting to get used to using it.  Explained below is the editor itself, and one example of editing a IR Satellite image in FX-Net.

The Color Map Editor

When you have an image (satellite, radar, numerical model image) loaded in the primary window on FX-Net, you may edit the image's colors.  Choosing  from the main tool bar opens the Color Map Editor.  You will use this editor to change/edit the colors of the loaded images. 

The Color Bar in the middle is the main place you work.  It is here you set the colors to change in the primary window.  There are two sections named Upper Color and Lower Color where you will select the colors for the color bar.  The Upper Color pertains to the top arrow, and the Lower Color to the bottom arrow on the color bar.  At the bottom are the buttons to set, save, change and undo changes, as well as  to dismiss the window. 

When opened, the Color Map Editor has the range of colors in the middle color bar that are present or possible in the image(s) loaded in the primary window.  To change these colors, you slide the arrows that are on top left and bottom right of the color bar.  You do this by clicking and moving them directly, or using the arrows to the left and right of the color bar.  Then you apply colors to the arrows and Fill or Interpolate.  When you have the colors edited in the color bar the way you want them, you Apply them to the images in the primary window. 

Next is a more in-depth discussion of the different sections in the Color Map Editor window. 


 

The Upper Color and Lower Color sections





With the RGB slider bars, you can control the color in the Color Wheel to the right.  The large box on the right side of the dialog box contains the Color Wheel.  When the editor is in its default mode, the top Color Wheel has the RGB values set to zero.  Consequently the Color Wheel is black.  Increasing the brightness value makes the wheel visible.  The Color Wheel Centroid (a circle with a dot in the middle) can be dragged around the Color Wheel to change the color in the Color Swatch, which is above the Set button. Also, clicking anywhere in the top half of the Color Bar (located in the middle of the dialog box), fills the top Color Swatch with the corresponding color; clicking anywhere in the lower half of the Color Bar fills the bottom Color Swatch. The Set buttons insert a narrow line of color into the current Color Bar at the location of the Color Pointer.  The color inserted is the one displayed in the corresponding (i.e., upper or lower) Color Swatch.  The Fill buttons replace the colors contained within the range specified by the Color Pointers in the Color Bar with the colors in the upper or lower Color Swatch.

The Color Bar


The Color Bar contains the color table of the current image and is located in the middle of the dialog box.  The arrowhead Color Pointers along the top and bottom halves of the Color Bar can be dragged to delineate a range of the color table; that is, the portion of the Color Bar contained between the top and bottom arrows. The Color Pointers move independently of one another, but they cannot move past each other.   As the Color Pointers are dragged along the Color Bar, they display the image values corresponding to the color pointed to. Thus, for example, if an infrared  satellite image is displayed, moving the Color Pointer shows the temperature  values corresponding to the colors in the Color Bar.  Note: As the Color Pointers are moved, they are filled with the color they are pointing to.  To either side of the Color Bar are left- and right-pointing arrows. These are used to move the Color Pointers along the Color Bar an increment at a time. The “>” and “<” Buttons move the Color Pointers in smaller increments than the “>>” and “<<” Buttons.


Edit Controls


Interpolate: This button fills the specified range with a (RGB)  interpolation between the colors in the upper and lower Color Swatches. 
Undo: This button allows you to successively undo changes made to the color table. (Not available at this time)
Redo: This button successively redoes the last edit that was undone. (Not available at this time)
Revert: This button returns the Color Bar (and the displayed image) to its original state.
Save: This button saves changes that you have made to a color table. If you are editing a read-only color table, or one that is owned by another user, this menu button is disabled.
Save As...: A menu button that opens the Save As Dialog Box in which you can enter a name for your color table. The color table is saved in a file containing the customized color tables for the current user. If the new name of the color table is the same as a name of an existing color table in this file, a dialog box opens and asks you if you want to overwrite in existing color table.
Load...:  Opens the folder with saved color tables; for example,if you have a color table saved for IR imagery, you can open the folder using Load and select it, the changes are made automatically to the Color Map Editor, than hit Apply.
Dismiss:  Closes the Color Map Editor
Apply:  Applies the changes made in the Color Map Editor to the images in the primary window. 

Editing IR Satellite Imagery



Shown above is an image from a loop of IR Satellite that was loaded in the FX-Net primary window.  We want to focus on only the colder temperatures, so we will edit out the warmer colors by making them black.  Once the loop has loaded, we select  from the tool bar and the Color Map Editor opens.  It looks like the Color Map Editor shown at the top when if first opens. 

As you can see, we will want to change any shades of grey and white to all black, so that we may just see temperatures less than -29.5C.  I slide the bottom Color Pointer to the left to encompass (between the Pointers) the region of colors in the color bar that need to be edited.  The Color Map Editor on the right shows what has been done. Next, we need to change the colors in the Color Bar that are between the two arrows.  We will make it all black, so all that will be left are the colors representing the coldest temperatures. 

 


 
Next, we change the color in the Color Bar between the Pointers to all black. This can be done two ways. 

The easiest method is to use the color (black) already selected in the Upper Color editor.  I simply click Fill, and the Editor fills the area between the arrows in the color bar with the color selected in the Upper Color Swatch.  Fill is the quickest way to change a range of the color bar to all one color.  As you can see to the left, I clicked Fill in the Upper Color editor and the color bar was filled black between the arrows.  Now I select Apply from the bottom of the Editor, and the images present in the primary window are changed.  The final image is below. 

Another method would be to use the Lower Color editor to change the color of the bottom Color Pointer from white to black, then Interpolate.  If you haven't noticed, as you slide the arrow along the color bar, it changes color.  The color of the Pointer represents what color it is pointing to in the color bar.   First, I would move the bottom Pointer to the left (shown above) to center the region of colors  between the arrows that I want to edit, and then change the color in the Lower Color Color Swatch to black by sliding the RGB slider bars all the way to the left.  The circle would now be black  in the Lower Color editor (like the Upper Color editor).  Then I select Set, which would set the color of the lower Pointer to black and insert a black line in the Color Bar at the Pointer, and finally Interpolate, which would fill the region between the arrows of the color bar black, as it is interpolating from black (left Pointer) to black (right Pointer). 


Either way, the final image looks like this one.

Saving color edits as a Color Table

When you have edited the images in the primary window, you may save these changes as a Color Table.  For example, if I wanted to use the color edit shown above many times, I may save it as a Color Table and call it up and apply it, instead of making the edits to the Color Bar each time.  To do this, when the images have been changed, simply click Save As... and a dialog box opens with the folder of Color Tables.  You name your Color Table and click Save.

The next time you load IR imagery and you want to apply the Color Table, simply open the Color Map Editor and click Load.  This opens the folder containing the Color Tables, and you select the appropriate one and click Open.  This loads the changes in the Color Bar and you then select Apply and the changes are made to your images.


Changing back to the original image is not a problem either in FX-Net.  If you have closed the Color Map Editor, open it again by clicking  on the main tool bar.  It will open showing the changes you have made to the images in the primary window.  Simply click Revert and the Color Map Editor and the images in the primary window will revert to the original configuration.  Then you can redo the changes if you want to try again.

Using the Color Map Editor takes practice to find out how it interpolates colors, and to find out what images it works best for.  When you change the colors, it changes all the images in the loop.  Also, if you make changes to an image, you may save these changes in a Procedure.