skyview.process.deedger

Class BoundaryAverage

java.lang.Object

skyview.process.Processor

skyview.process.deedger.BoundaryAverage

All Implemented Interfaces:

java.io.Serializable, Component

public class BoundaryAverage
extends Processor

This class adjusts the 0 point for data taken from multiple images to try to minize edge effects. The alogithm used in this version is as follows:

1. Find all of the 'edge' pixels in the image and compute the jump over the edge.
   • We determine the edge pixels by looking at the source images of pixels which differ by one in the x or y dimension. We sweep in both directions
   • The jump is simply the change in value between the two pixels.
2. Add the jump at each edge pixel to the any previous jumps for these two source images. When we finish we have a matrix of the total deltas along the edges shared by each pair of images. We compute the delta's in both directions, so that deltas[a][b] = - deltas[b][a] Also keep track of the number of edge pixels for each pair of images. [Note that many of the candidate images will not have been used in any pixels in the output image. This will simply correspond to empty rows and columsn in the deltas and counts matrices.]
3. Create an offset array with a NaN offset for each input image.
4. Find the source image which has the maximum number of pixels in the output image. Make this the base image with an offset of 0.
5. Consider the source images in two sets: the set for which an offset has been defined, and a set for which it has not. Initially only the base image is in the first set and all others are in the undefined set.
6. Find the largest entry in the counts matrix where the row corresponds to an image with a defined offset, and the column corresponds to an image with an undefined offset.
7. Assign an offset to the image associcated with the column such that the total delta along the edge should become 0. Remember that the defined image will change too.
8. Iterate until all images have an offset defined.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
BoundaryAverage()

Method Summary

Modifier and Type	Method and Description
java.lang.String	getDescription() Get a description of this object
java.lang.String	getName() Get a name for this object
void	process(Image[] inputs, Image output, int[] source, Sampler samp, DepthSampler dsamp) Initialized the de-edger.
void	updateHeader(nom.tam.fits.Header h) Update a FITS header with the processing done here.
boolean	updatesOutput() Does this processor actually modify the output array?

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BoundaryAverage

public BoundaryAverage()

Method Detail

updatesOutput

public boolean updatesOutput()

Description copied from class: Processor

Does this processor actually modify the output array?

Specified by:

updatesOutput in class Processor

getName

public java.lang.String getName()

Get a name for this object

getDescription

public java.lang.String getDescription()

Get a description of this object

process

public void process(Image[] inputs,
                    Image output,
                    int[] source,
                    Sampler samp,
                    DepthSampler dsamp)

Initialized the de-edger.

Specified by:

process in class Processor

Parameters:

inputs - The input images.

output - The output user image

source - The index array

samp - The spatial sampler (not used)

dsamp - The energy sampler (not used)

updateHeader

public void updateHeader(nom.tam.fits.Header h)

Update a FITS header with the processing done here.

Specified by:

updateHeader in class Processor