java.awt.image.AreaAveragingScaleFilter Maven / Gradle / Ivy

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This work corresponds to the API signatures of JSR 217: Personal Basis Profile 1.1. In the event of a discrepency between this work and the JSR 217 specification, which is available at http://www.jcp.org/en/jsr/detail?id=217, the latter takes precedence. */ package java.awt.image; import java.awt.image.ImageConsumer; import java.awt.image.ColorModel; import java.util.Hashtable; import java.awt.Rectangle; /** * An ImageFilter class for scaling images using a simple area averaging * algorithm that produces smoother results than the nearest neighbor * algorithm. *

This class extends the basic ImageFilter Class to scale an existing * image and provide a source for a new image containing the resampled * image. The pixels in the source image are blended to produce pixels * for an image of the specified size. The blending process is analogous * to scaling up the source image to a multiple of the destination size * using pixel replication and then scaling it back down to the destination * size by simply averaging all the pixels in the supersized image that * fall within a given pixel of the destination image. If the data from * the source is not delivered in TopDownLeftRight order then the filter * will back off to a simple pixel replication behavior and utilize the * requestTopDownLeftRightResend() method to refilter the pixels in a * better way at the end. *

It is meant to be used in conjunction with a FilteredImageSource * object to produce scaled versions of existing images. Due to * implementation dependencies, there may be differences in pixel values * of an image filtered on different platforms. * * @see FilteredImageSource * @see ReplicateScaleFilter * @see ImageFilter * * @version 1.14 01/23/03 * @author Jim Graham */ public class AreaAveragingScaleFilter extends ReplicateScaleFilter { /** * Constructs an AreaAveragingScaleFilter that scales the pixels from * its source Image as specified by the width and height parameters. * @param width the target width to scale the image * @param height the target height to scale the image */ public AreaAveragingScaleFilter(int width, int height) { super(0,0); } /** * Detect if the data is being delivered with the necessary hints * to allow the averaging algorithm to do its work. *

* Note: This method is intended to be called by the * ImageProducer of the Image whose * pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ImageConsumer#setHints */ public void setHints(int hints) { } /** * Combine the components for the delivered byte pixels into the * accumulation arrays and send on any averaged data for rows of * pixels that are complete. If the correct hints were not * specified in the setHints call then relay the work to our * superclass which is capable of scaling pixels regardless of * the delivery hints. *

* Note: This method is intended to be called by the * ImageProducer of the Image * whose pixels are being filtered. Developers using * this class to filter pixels from an image should avoid calling * this method directly since that operation could interfere * with the filtering operation. * @see ReplicateScaleFilter */ public void setPixels(int x, int y, int w, int h, java.awt.image.ColorModel model, byte[] pixels, int off, int scansize) { } /** * Combine the components for the delivered int pixels into the * accumulation arrays and send on any averaged data for rows of * pixels that are complete. If the correct hints were not * specified in the setHints call then relay the work to our * superclass which is capable of scaling pixels regardless of * the delivery hints. *