FileDocCategorySizeDatePackage
CropImageFilter.javaAPI DocJava SE 5 API5619Fri Aug 26 14:56:54 BST 2005java.awt.image

CropImageFilter

public class CropImageFilter extends ImageFilter
An ImageFilter class for cropping images. This class extends the basic ImageFilter Class to extract a given rectangular region of an existing Image and provide a source for a new image containing just the extracted region. It is meant to be used in conjunction with a FilteredImageSource object to produce cropped versions of existing images.
see
FilteredImageSource
see
ImageFilter
version
1.18 07/16/04
author
Jim Graham

Fields Summary
int
cropX
int
cropY
int
cropW
int
cropH
Constructors Summary
public CropImageFilter(int x, int y, int w, int h)
Constructs a CropImageFilter that extracts the absolute rectangular region of pixels from its source Image as specified by the x, y, w, and h parameters.

param
x the x location of the top of the rectangle to be extracted
param
y the y location of the top of the rectangle to be extracted
param
w the width of the rectangle to be extracted
param
h the height of the rectangle to be extracted

	cropX = x;
	cropY = y;
	cropW = w;
	cropH = h;
Methods Summary
private intaddWithoutOverflow(int x, int w)

        int x2 = x + w;
        if ( x > 0 && w > 0 && x2 < 0 ) {
            x2 = Integer.MAX_VALUE;
        } else if( x < 0 && w < 0 && x2 > 0 ) {
            x2 = Integer.MIN_VALUE;
        }
        return x2;
public voidsetDimensions(int w, int h)
Override the source image's dimensions and pass the dimensions of the rectangular cropped region to the ImageConsumer.

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

	consumer.setDimensions(cropW, cropH);
public voidsetPixels(int x, int y, int w, int h, java.awt.image.ColorModel model, byte[] pixels, int off, int scansize)
Determine whether the delivered byte pixels intersect the region to be extracted and passes through only that subset of pixels that appear in the output region.

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.

	int x1 = x;
	if (x1 < cropX) {
	    x1 = cropX;
	}
    int x2 = addWithoutOverflow(x, w);
	if (x2 > cropX + cropW) {
	    x2 = cropX + cropW;
	}
	int y1 = y;
	if (y1 < cropY) {
	    y1 = cropY;
	}

    int y2 = addWithoutOverflow(y, h);
	if (y2 > cropY + cropH) {
	    y2 = cropY + cropH;
	}
	if (x1 >= x2 || y1 >= y2) {
	    return;
	}
	consumer.setPixels(x1 - cropX, y1 - cropY, (x2 - x1), (y2 - y1),
			   model, pixels,
			   off + (y1 - y) * scansize + (x1 - x), scansize);
public voidsetPixels(int x, int y, int w, int h, java.awt.image.ColorModel model, int[] pixels, int off, int scansize)
Determine if the delivered int pixels intersect the region to be extracted and pass through only that subset of pixels that appear in the output region.

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.

	int x1 = x;
	if (x1 < cropX) {
	    x1 = cropX;
	}
    int x2 = addWithoutOverflow(x, w);
	if (x2 > cropX + cropW) {
	    x2 = cropX + cropW;
	}
	int y1 = y;
	if (y1 < cropY) {
	    y1 = cropY;
	}

    int y2 = addWithoutOverflow(y, h);
	if (y2 > cropY + cropH) {
	    y2 = cropY + cropH;
	}
	if (x1 >= x2 || y1 >= y2) {
	    return;
	}
	consumer.setPixels(x1 - cropX, y1 - cropY, (x2 - x1), (y2 - y1),
			   model, pixels,
			   off + (y1 - y) * scansize + (x1 - x), scansize);
public voidsetProperties(java.util.Hashtable props)
Passes along the properties from the source object after adding a property indicating the cropped region. This method invokes super.setProperties, which might result in additional properties being added.

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.

	Hashtable<Object,Object> p = (Hashtable<Object,Object>)props.clone();
	p.put("croprect", new Rectangle(cropX, cropY, cropW, cropH));
	super.setProperties(p);