private void applyOverlay(
int gg0000,
WritableRaster raster,
int frameIndex,
ImageReadParam param,
int outBits,
byte[] ovlyData) {
Attributes ovlyAttrs = metadata.getAttributes();
int grayscaleValue = 0xffff;
if (param instanceof DicomImageReadParam) {
DicomImageReadParam dParam = (DicomImageReadParam) param;
Attributes psAttrs = dParam.getPresentationState();
if (psAttrs != null) {
if (psAttrs.containsValue(Tag.OverlayData | gg0000)) ovlyAttrs = psAttrs;
grayscaleValue = Overlays.getRecommendedDisplayGrayscaleValue(psAttrs, gg0000);
} else grayscaleValue = dParam.getOverlayGrayscaleValue();
}
Overlays.applyOverlay(
ovlyData != null ? 0 : frameIndex,
raster,
ovlyAttrs,
gg0000,
grayscaleValue >>> (16 - outBits),
ovlyData);
}
private int[] getActiveOverlayGroupOffsets(ImageReadParam param) {
if (param instanceof DicomImageReadParam) {
DicomImageReadParam dParam = (DicomImageReadParam) param;
Attributes psAttrs = dParam.getPresentationState();
if (psAttrs != null) return Overlays.getActiveOverlayGroupOffsets(psAttrs);
else
return Overlays.getActiveOverlayGroupOffsets(
metadata.getAttributes(), dParam.getOverlayActivationMask());
}
return Overlays.getActiveOverlayGroupOffsets(metadata.getAttributes(), 0xffff);
}
private byte[] extractOverlay(int gg0000, WritableRaster raster) {
Attributes attrs = metadata.getAttributes();
if (attrs.getInt(Tag.OverlayBitsAllocated | gg0000, 1) == 1) return null;
int ovlyRows = attrs.getInt(Tag.OverlayRows | gg0000, 0);
int ovlyColumns = attrs.getInt(Tag.OverlayColumns | gg0000, 0);
int bitPosition = attrs.getInt(Tag.OverlayBitPosition | gg0000, 0);
int mask = 1 << bitPosition;
int length = ovlyRows * ovlyColumns;
byte[] ovlyData = new byte[(((length + 7) >>> 3) + 1) & (~1)];
Overlays.extractFromPixeldata(raster, mask, ovlyData, 0, length);
return ovlyData;
}