McIDAS Learning Guide
Version 2006

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GUI - Modifying Image and Graphics Colors

Modifying Image Colors

In this exercise, you will display an infrared image over the United States from the Blizzard dataset, restore the default enhancement, and modify the image and graphics colors.
  1. Display the 18:01:00 UTC infrared satellite image from 13 MAR 1993 on the current frame. Display a map on the image.
    In the Display/Image GUI, select: the BLIZZARD/G7-IR-4K dataset, and to display a map on the image.
    Select the 18:01:00 UTC image from the image list, load the image, and dismiss the Image Select window.
  2. Obviously, these colors are not the colors of a normal infrared image. Even though the frames were erased, the NEXRAD enhancement is still assigned to that frame. So, you'll need to restore the correct colors by modifying the Image Colors.
    Select: Colors/Change Image Colors
    Click:   the Reset tab
    The default option in the Reset tab is to reset the current frame only.
    Click:   Reset
  3. Activate the GUI where you'll create your own enhancement.
    Click:   Make
    The Make tab of the Image Colors GUI contains four options in which you can change or create image colors: 'Using Color Names,' 'Using Color Intensities,' 'Using ENH,' and 'Using EB.'
    Start out by using the predefined McIDAS colors.
    Click:   Using Color Names
  4. Use the predefined color 'Blue' to begin at a grayscale of 145, and 'Goldenrod' to end at a grayscale of 210.
    Slide:   the Begin scrollbar to 145.
    Slide:   the End scrollbar to 210.
    Select:  Beginning Color/Blue
    Select:  Ending Color/Goldenrod
    Click:   Apply Enhancement

    Look at the Image window. You should see that all brightness values from 145 to 210 are colored from Blue to Goldenrod, depending on the specific value. All other brightness values will remain in their original grayscale form.

  5. Repeat Step 4 several times, changing the colors and input values each time.

  6. Once you have finished altering the image colors, dismiss the color selection GUI and save the enhancement as LEARNING.ET.
    Click:   Dismiss
    Click:   Save
    Type:   LEARNING
    Click:   Save
  7. Reset the original image enhancement and restore LEARNING.ET to the image once again.
    Click:   Restore
    Select:  Select Enhancement File/LEARNING.ET
    Click:   Restore
  8. Restore the original image enhancement.
    Click:   Reset
    Select:  Frame Selection/Set for Current Loop
    Click:   Reset
    Click:   Dismiss

Modifying Graphics Colors

  1. Change the color of the map in frame 4.
    Select:  Colors/Change Graphic Colors
    Click:   Create a New Color
    Slide:   the Red, Green, and Blue Intensity bars until you've created a color you like.
    Click:   Apply Enhancement
    Click:   Dismiss
    Look at the image window, and you will notice the changes to graphic color 1 took effect immediately.

  2. Save the new graphics table as LEARNING.GRX.
    Click:   Save
    Type:   LEARNING in the File Name field
    Click:   Save
  3. Restore the default graphics colors.
    Click:   Reset
    Select:  Frame Selection/Current Frame Only
    Click:   Reset
  4. Close the Graphics Colors window.
    Click:   Dismiss

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