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Creating Animations

Use Animation to create a movie out of images from one or more open files.

Selecting Bands for Animation

  1. From the Image window menu bar, select Tools  Animation.

    2.  

  2. When the Animation Input Parameters dialog appears,choose from the following options.

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    Note
    All of the bands from the currently displayed image are selected for animation by default.

    • To select additional bands from files of the same size, click on the bands with the left mouse button while pressing the Ctrl key on your keyboard.

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    • To clear individual bands from the list if they are already selected, click on the desired band with the left mouse button while pressing the Ctrl key on your keyboard.

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    • To use subsetting to reduce the size of the image to animate, click Spatial Subset. For subsetting details, see Selecting a Spatial Subset.

     

  3. Set the desired size of the animation display window by entering values in the boxes next to the Window Size text label.

    4.  


    Note
    Note that the selected images are automatically resized to the selected window size. Reducing either the spatial subset to animate and/or the size of the animation window enhances the speed of the animation.

     

  4. Select a resampling method by clicking the Aggregate or Nearest Neighbor button. Nearest neighbor resampling uses the nearest pixel value in the animation window and aggregate averages all the pixel values that contribute to the output animation pixel. For example, if your animation window size is half the size of the image, the nearest neighbor method will use every other pixel and every other line to create the image in the animation window and the aggregate method will average four pixels to create the output image.

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  5. Click OK to start the animation.

When the animation is activated, the individual selected bands are automatically subset, resampled, and loaded into the Animation widow. A status bar appears as each image is processed.

After all of the selected images are loaded, the animation starts automatically. Each selected band displays sequentially.

Controlling Animation Characteristics

After the animation is loaded, you can specify the animation characteristics.

The following table describes the available options in the Animation window:

Table 4-9: Animation Window Controls

Table 4-9: Animation Window Controls
Option
Description

To set the animation speed, enter a number from 0 to 100 into the Speed text box, or use the arrow buttons to set the speed.

To turn the real-time frame number slider on and off, select Options  Update Slider:On/Off from the menu at the top of the Animation window.

Click to display the animation from the highest frame to lowest.

Click to display the animation from lowest frame to the highest.

Click to display the animation from the lowest frame to the highest frame and back again.

Click to pause the animation at the current frame.

Saving Animations

You can save an animation as an MPEG (Moving Picture Experts Group) file.


Note
Saving an animation as an MPEG file requires a special license. For more information, contact your Research Systems sales representative or technical support.

  1. Select File  Save Animation as MPEG. The Output Sequence to MPEG Parameters dialog appears.

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  2. From the MPEG Frame Rate drop-down button, select a frame rate in frames per second.

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  3. In the MPEG Quality text box, enter a compression quality value between 0 and 100, or use the arrow buttons to set the value.

    4.  

    The compression is a lossy compression where 0 is lowest quality and 100 is highest quality (no compression). Entering a compression quality factor less than 100 decreases the amount of disk space used to store the MPEG output.

     


    Note
    A duplication factor helps to make the MPEG output appear smoother. To duplicate frames in the MPEG output, enter or select a Duplicate frames number.

     

  4. Enter or choose an output filename and click OK.

Cancelling Animations

To cancel the animation at any time, select File  Cancel from the Animation window menu.

  ENVI Online Help (August 12, 2005)