// This method returns true if the specified image has transparent pixels
// Source: http://www.exampledepot.com/egs/java.awt.image/HasAlpha.html
public static boolean hasAlpha(Image image) {
// If buffered image, the color model is readily available
if (image instanceof BufferedImage) {
BufferedImage bimage = (BufferedImage) image;
return bimage.getColorModel().hasAlpha();
}
// Use a pixel grabber to retrieve the image's color model;
// grabbing a single pixel is usually sufficient
PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
try {
pg.grabPixels();
} catch (InterruptedException e) {
}
// Get the image's color model
ColorModel cm = pg.getColorModel();
return cm.hasAlpha();
}
public void write(BufferedImage image, AVList params) throws IOException {
if (image == null) {
String msg = Logging.getMessage("nullValue.ImageSource");
Logging.logger().severe(msg);
throw new IllegalArgumentException(msg);
}
if (0 == image.getWidth() || 0 == image.getHeight()) {
String msg =
Logging.getMessage("generic.InvalidImageSize", image.getWidth(), image.getHeight());
Logging.logger().severe(msg);
throw new IllegalArgumentException(msg);
}
if (null == params || 0 == params.getValues().size()) {
String reason = Logging.getMessage("nullValue.AVListIsNull");
Logging.logger().finest(Logging.getMessage("GeotiffWriter.GeoKeysMissing", reason));
params = new AVListImpl();
} else {
this.validateParameters(params, image.getWidth(), image.getHeight());
}
// how we proceed in part depends upon the image type...
int type = image.getType();
// handle CUSTOM type which comes from our GeoTiffreader (for now)
if (BufferedImage.TYPE_CUSTOM == type) {
int numColorComponents = 0, numComponents = 0, pixelSize = 0, dataType = 0, csType = 0;
boolean hasAlpha = false;
if (null != image.getColorModel()) {
ColorModel cm = image.getColorModel();
numColorComponents = cm.getNumColorComponents();
numComponents = cm.getNumComponents();
pixelSize = cm.getPixelSize();
hasAlpha = cm.hasAlpha();
ColorSpace cs = cm.getColorSpace();
if (null != cs) csType = cs.getType();
}
if (null != image.getSampleModel()) {
SampleModel sm = image.getSampleModel();
dataType = sm.getDataType();
}
if (dataType == DataBuffer.TYPE_FLOAT && pixelSize == Float.SIZE && numComponents == 1) {
type = BufferedImage_TYPE_ELEVATION_FLOAT32;
} else if (dataType == DataBuffer.TYPE_SHORT
&& pixelSize == Short.SIZE
&& numComponents == 1) {
type = BufferedImage_TYPE_ELEVATION_SHORT16;
} else if (ColorSpace.CS_GRAY == csType && pixelSize == Byte.SIZE) {
type = BufferedImage.TYPE_BYTE_GRAY;
} else if (dataType == DataBuffer.TYPE_USHORT
&& ColorSpace.CS_GRAY == csType
&& pixelSize == Short.SIZE) {
type = BufferedImage.TYPE_USHORT_GRAY;
} else if (ColorSpace.TYPE_RGB == csType
&& pixelSize == 3 * Byte.SIZE
&& numColorComponents == 3) {
type = BufferedImage.TYPE_3BYTE_BGR;
} else if (ColorSpace.TYPE_RGB == csType
&& hasAlpha
&& pixelSize == 4 * Byte.SIZE
&& numComponents == 4) {
type = BufferedImage.TYPE_4BYTE_ABGR;
}
}
switch (type) {
case BufferedImage.TYPE_3BYTE_BGR:
case BufferedImage.TYPE_4BYTE_ABGR:
case BufferedImage.TYPE_4BYTE_ABGR_PRE:
case BufferedImage.TYPE_INT_RGB:
case BufferedImage.TYPE_INT_BGR:
case BufferedImage.TYPE_INT_ARGB:
case BufferedImage.TYPE_INT_ARGB_PRE:
{
this.writeColorImage(image, params);
}
break;
case BufferedImage.TYPE_USHORT_GRAY:
case BufferedImage.TYPE_BYTE_GRAY:
{
this.writeGrayscaleImage(image, params);
}
break;
case BufferedImage_TYPE_ELEVATION_SHORT16:
case BufferedImage_TYPE_ELEVATION_FLOAT32:
{
String msg = Logging.getMessage("GeotiffWriter.FeatureNotImplementedd", type);
Logging.logger().severe(msg);
throw new IllegalArgumentException(msg);
}
// break;
case BufferedImage.TYPE_CUSTOM:
default:
{
ColorModel cm = image.getColorModel();
SampleModel sm = image.getSampleModel();
StringBuffer sb =
new StringBuffer(Logging.getMessage("GeotiffWriter.UnsupportedType", type));
sb.append("\n");
sb.append("NumBands=").append(sm.getNumBands()).append("\n");
sb.append("NumDataElements=").append(sm.getNumDataElements()).append("\n");
sb.append("NumColorComponents=").append(cm.getNumColorComponents()).append("\n");
sb.append("NumComponents=").append(cm.getNumComponents()).append("\n");
sb.append("PixelSize=").append(cm.getPixelSize()).append("\n");
sb.append("hasAlpha=").append(cm.hasAlpha());
String msg = sb.toString();
Logging.logger().severe(msg);
throw new IllegalArgumentException(msg);
}
}
}