/** Performs actual projection using specified method. */
public void doProjection() {
if (imp == null) return;
sliceCount = 0;
if (method < AVG_METHOD || method > MEDIAN_METHOD) method = AVG_METHOD;
for (int slice = startSlice; slice <= stopSlice; slice += increment) sliceCount++;
if (method == MEDIAN_METHOD) {
projImage = doMedianProjection();
return;
}
// Create new float processor for projected pixels.
FloatProcessor fp = new FloatProcessor(imp.getWidth(), imp.getHeight());
ImageStack stack = imp.getStack();
RayFunction rayFunc = getRayFunction(method, fp);
if (IJ.debugMode == true) {
IJ.log("\nProjecting stack from: " + startSlice + " to: " + stopSlice);
}
// Determine type of input image. Explicit determination of
// processor type is required for subsequent pixel
// manipulation. This approach is more efficient than the
// more general use of ImageProcessor's getPixelValue and
// putPixel methods.
int ptype;
if (stack.getProcessor(1) instanceof ByteProcessor) ptype = BYTE_TYPE;
else if (stack.getProcessor(1) instanceof ShortProcessor) ptype = SHORT_TYPE;
else if (stack.getProcessor(1) instanceof FloatProcessor) ptype = FLOAT_TYPE;
else {
IJ.error("Z Project", "Non-RGB stack required");
return;
}
// Do the projection.
for (int n = startSlice; n <= stopSlice; n += increment) {
IJ.showStatus("ZProjection " + color + ": " + n + "/" + stopSlice);
IJ.showProgress(n - startSlice, stopSlice - startSlice);
projectSlice(stack.getPixels(n), rayFunc, ptype);
}
// Finish up projection.
if (method == SUM_METHOD) {
fp.resetMinAndMax();
projImage = new ImagePlus(makeTitle(), fp);
} else if (method == SD_METHOD) {
rayFunc.postProcess();
fp.resetMinAndMax();
projImage = new ImagePlus(makeTitle(), fp);
} else {
rayFunc.postProcess();
projImage = makeOutputImage(imp, fp, ptype);
}
if (projImage == null) IJ.error("Z Project", "Error computing projection.");
}
/**
* Handles mechanics of projection by selecting appropriate pixel array type. We do this rather
* than using more general ImageProcessor getPixelValue() and putPixel() methods because direct
* manipulation of pixel arrays is much more efficient.
*/
private void projectSlice(Object pixelArray, RayFunction rayFunc, int ptype) {
switch (ptype) {
case BYTE_TYPE:
rayFunc.projectSlice((byte[]) pixelArray);
break;
case SHORT_TYPE:
rayFunc.projectSlice((short[]) pixelArray);
break;
case FLOAT_TYPE:
rayFunc.projectSlice((float[]) pixelArray);
break;
}
}