ReplicateScaleFilterpublic class ReplicateScaleFilter extends ImageFilter | An ImageFilter class for scaling images using the simplest 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 sampled to produce pixels
for an image of the specified size by replicating rows and columns of
pixels to scale up or omitting rows and columns of pixels to scale
down.
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. |
| Fields Summary |
|---|
| protected int | srcWidthThe width of the source image. | | protected int | srcHeightThe height of the source image. | | protected int | destWidthThe target width to scale the image. | | protected int | destHeightThe target height to scale the image. | | protected int[] | srcrowsAn int array containing information about a
row of pixels. | | protected int[] | srccolsAn int array containing information about a
column of pixels. | | protected Object | outpixbufA byte array initialized with a size of
{@link #destWidth} and used to deliver a row of pixel
data to the {@link ImageConsumer}. |
| Constructors Summary |
|---|
public ReplicateScaleFilter(int width, int height)Constructs a ReplicateScaleFilter that scales the pixels from
its source Image as specified by the width and height parameters.
if (width == 0 || height == 0) {
throw new IllegalArgumentException("Width ("+width+
") and height ("+height+
") must be non-zero");
}
destWidth = width;
destHeight = height;
|
| Methods Summary |
|---|
| private void | calculateMaps()
srcrows = new int[destHeight + 1];
for (int y = 0; y <= destHeight; y++) {
srcrows[y] = (2 * y * srcHeight + srcHeight) / (2 * destHeight);
}
srccols = new int[destWidth + 1];
for (int x = 0; x <= destWidth; x++) {
srccols[x] = (2 * x * srcWidth + srcWidth) / (2 * destWidth);
}
| | public void | setDimensions(int w, int h)Override the dimensions of the source image and pass the dimensions
of the new scaled size 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.
srcWidth = w;
srcHeight = h;
if (destWidth < 0) {
if (destHeight < 0) {
destWidth = srcWidth;
destHeight = srcHeight;
} else {
destWidth = srcWidth * destHeight / srcHeight;
}
} else if (destHeight < 0) {
destHeight = srcHeight * destWidth / srcWidth;
}
consumer.setDimensions(destWidth, destHeight);
| | public void | setPixels(int x, int y, int w, int h, java.awt.image.ColorModel model, byte[] pixels, int off, int scansize)Choose which rows and columns of the delivered byte pixels are
needed for the destination scaled image and pass through just
those rows and columns that are needed, replicated as necessary.
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.
if (srcrows == null || srccols == null) {
calculateMaps();
}
int sx, sy;
int dx1 = (2 * x * destWidth + srcWidth - 1) / (2 * srcWidth);
int dy1 = (2 * y * destHeight + srcHeight - 1) / (2 * srcHeight);
byte outpix[];
if (outpixbuf != null && outpixbuf instanceof byte[]) {
outpix = (byte[]) outpixbuf;
} else {
outpix = new byte[destWidth];
outpixbuf = outpix;
}
for (int dy = dy1; (sy = srcrows[dy]) < y + h; dy++) {
int srcoff = off + scansize * (sy - y);
int dx;
for (dx = dx1; (sx = srccols[dx]) < x + w; dx++) {
outpix[dx] = pixels[srcoff + sx - x];
}
if (dx > dx1) {
consumer.setPixels(dx1, dy, dx - dx1, 1,
model, outpix, dx1, destWidth);
}
}
| | public void | setPixels(int x, int y, int w, int h, java.awt.image.ColorModel model, int[] pixels, int off, int scansize)Choose which rows and columns of the delivered int pixels are
needed for the destination scaled image and pass through just
those rows and columns that are needed, replicated as necessary.
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.
if (srcrows == null || srccols == null) {
calculateMaps();
}
int sx, sy;
int dx1 = (2 * x * destWidth + srcWidth - 1) / (2 * srcWidth);
int dy1 = (2 * y * destHeight + srcHeight - 1) / (2 * srcHeight);
int outpix[];
if (outpixbuf != null && outpixbuf instanceof int[]) {
outpix = (int[]) outpixbuf;
} else {
outpix = new int[destWidth];
outpixbuf = outpix;
}
for (int dy = dy1; (sy = srcrows[dy]) < y + h; dy++) {
int srcoff = off + scansize * (sy - y);
int dx;
for (dx = dx1; (sx = srccols[dx]) < x + w; dx++) {
outpix[dx] = pixels[srcoff + sx - x];
}
if (dx > dx1) {
consumer.setPixels(dx1, dy, dx - dx1, 1,
model, outpix, dx1, destWidth);
}
}
| | public void | setProperties(java.util.Hashtable props)Passes along the properties from the source object after adding a
property indicating the scale applied.
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();
String key = "rescale";
String val = destWidth + "x" + destHeight;
Object o = p.get(key);
if (o != null && o instanceof String) {
val = ((String) o) + ", " + val;
}
p.put(key, val);
super.setProperties(p);
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