### Chapter 8: Frequency Domain

## SpectralProbe

The `SpectralProbe` application displays an input image and the spectrum of a small region within that image. The user may select region sizes of 16x16, 32x32 and 64x64. The position of the region is chosen with a left mouse click when the cursor is over the point of interest on the image. A windowing function can be applied to the spectrum, to reduce the effect of discontinuity at the edges of the region.

The file `SpectralProbe.java` compiles to produce

      SpectralProbe.class
      SpectralProbe$1.class
      SpectralProbe$Controls.class
      SpectralProbe$Display.class

These `.class` files have been packaged as a single JAR file, `SpectralProbe.jar`. You can install the application by copying this JAR file, along with either the MS-DOS batch file `SpectralProbe.bat` or the bash shell script `SpectralProbe.sh`, as appropriate. The batch file or script should be edited to reflect the new location of the JAR file.