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*
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package java.awt.image;
/**
* This abstract class defines a lookup table object. ByteLookupTable
* and ShortLookupTable are subclasses, which
* contain byte and short data, respectively. A lookup table
* contains data arrays for one or more bands (or components) of an image
* (for example, separate arrays for R, G, and B),
* and it contains an offset which will be subtracted from the
* input values before indexing into the arrays. This allows an array
* smaller than the native data size to be provided for a
* constrained input. If there is only one array in the lookup
* table, it will be applied to all bands. All arrays must be the
* same size.
*
* @see ByteLookupTable
* @see ShortLookupTable
* @see LookupOp
*/
public abstract class LookupTable extends Object{
/**
* Constants
*/
int numComponents;
int offset;
int numEntries;
/**
* Constructs a new LookupTable from the number of components and an offset
* into the lookup table.
* @param offset the offset to subtract from input values before indexing
* into the data arrays for this <code>LookupTable</code>
* @param numComponents the number of data arrays in this
* <code>LookupTable</code>
* @throws IllegalArgumentException if <code>offset</code> is less than 0
* or if <code>numComponents</code> is less than 1
*/
protected LookupTable(int offset, int numComponents) {
if (offset < 0) {
throw new
IllegalArgumentException("Offset must be greater than 0");
}
if (numComponents < 1) {
throw new IllegalArgumentException("Number of components must "+
" be at least 1");
}
this.numComponents = numComponents;
this.offset = offset;
}
/**
* Returns the number of components in the lookup table.
* @return the number of components in this <code>LookupTable</code>.
*/
public int getNumComponents() {
return numComponents;
}
/**
* Returns the offset.
* @return the offset of this <code>LookupTable</code>.
*/
public int getOffset() {
return offset;
}
/**
* Returns an <code>int</code> array of components for
* one pixel. The <code>dest</code> array contains the
* result of the lookup and is returned. If dest is
* <code>null</code>, a new array is allocated. The
* source and destination can be equal.
* @param src the source array of components of one pixel
* @param dest the destination array of components for one pixel,
* translated with this <code>LookupTable</code>
* @return an <code>int</code> array of components for one
* pixel.
*/
public abstract int[] lookupPixel(int[] src, int[] dest);
}