/**
* Generates a zero crossing mask for a 2D function. Sets a ModelImage to 255 if a zero crossing
* is detected.
*
* @param slice the slice of the volume which we are working on (0 if from 2D image)
* @param buffer array in which to find zero crossing
* @param detectionType the type of zero crossing detection to perform
*/
public void genZeroXMask(int slice, float[] buffer, int detectionType) {
float x0, x1, x2, x3;
int i0, i1, i2, i3;
int i, j;
int indexY;
int length;
int xDim = srcImage.getExtents()[0];
int yDim = srcImage.getExtents()[1];
length = xDim * yDim;
int xxDim = xDim - 1;
int yyDim = yDim - 1;
float level = 0;
int offset = slice * length;
for (j = 0; j < yyDim; j++) {
indexY = j * xDim;
for (i = 0; i < xxDim; i++) {
i0 = indexY + i;
if (detectionType == MARCHING_SQUARES) {
i1 = i0 + 1;
i2 = i0 + xDim;
i3 = i0 + 1 + xDim;
x0 = buffer[i0];
x1 = buffer[i1];
x2 = buffer[i2];
x3 = buffer[i3];
if ((x0 >= level)
&& (x1 >= level)
&& (x2 >= level)
&& (x3 >= level)) { // case 0 - no edge
} else if ((x0 >= level) && (x1 >= level) && (x2 < level) && (x3 >= level)) {
// case 1 - edge in the lower left
zXMask.set(offset + i2, 255);
} else if ((x0 >= level) && (x1 >= level) && (x2 >= level) && (x3 < level)) {
// case 2 - edge in the lower right
zXMask.set(offset + i3, 255);
} else if ((x0 >= level) && (x1 >= level) && (x2 < level) && (x3 < level)) {
// case 3 - edge horizontally
zXMask.set(offset + i2, 255);
zXMask.set(offset + i3, 255);
} else if ((x0 >= level) && (x1 < level) && (x2 >= level) && (x3 >= level)) {
// case 4 - edge in the upper right
zXMask.set(offset + i1, 255);
} else if ((x0 >= level) && (x1 < level) && (x2 < level) && (x3 >= level)) {
// case 5 - ambiguous case; either edge in upper right and lower left or
// edge that goes from the upper right to the lower left
zXMask.set(offset + i1, 255);
zXMask.set(offset + i2, 255);
} else if ((x0 >= level) && (x1 < level) && (x2 >= level) && (x3 < level)) {
// case 6 - edge going vertically along the right
zXMask.set(offset + i1, 255);
zXMask.set(offset + i3, 255);
} else if ((x0 >= level) && (x1 < level) && (x2 < level) && (x3 < level)) {
// case 7 - edge in the upper left
zXMask.set(offset + i0, 255);
} else if ((x0 < level) && (x1 >= level) && (x2 >= level) && (x3 >= level)) {
// case 8 - edge in the upper left
zXMask.set(offset + i0, 255);
} else if ((x0 < level) && (x1 >= level) && (x2 < level) && (x3 >= level)) {
// case 9 - edge going vertically along the left
zXMask.set(offset + i0, 255);
zXMask.set(offset + i2, 255);
} else if ((x0 < level) && (x1 >= level) && (x2 >= level) && (x3 < level)) {
// case 10 - ambiguous case; either edge in upper left and lower right or
// edge that goes from the upper left to the lower right
zXMask.set(offset + i0, 255);
zXMask.set(offset + i3, 255);
} else if ((x0 < level) && (x1 >= level) && (x2 < level) && (x3 < level)) {
// case 11 - edge in the upper right
zXMask.set(offset + i1, 255);
} else if ((x0 < level) && (x1 < level) && (x2 >= level) && (x3 >= level)) {
// case 12 - edge going horizontally along the top
zXMask.set(offset + i0, 255);
zXMask.set(offset + i1, 255);
} else if ((x0 < level) && (x1 < level) && (x2 < level) && (x3 >= level)) {
// case 13 - edge in the lower right
zXMask.set(offset + i3, 255);
} else if ((x0 < level) && (x1 < level) && (x2 >= level) && (x3 < level)) {
// case 14 - edge in the lower left
zXMask.set(offset + i2, 255);
} else if ((x0 < level)
&& (x1 < level)
&& (x2 < level)
&& (x3 < level)) { // case 15 - no edge
}
} else if (detectionType == NEGATIVE_EDGES) {
if (buffer[i0] <= 1) {
zXMask.set(offset + i0, 255);
}
} else if (detectionType == OLD_DETECTION) {
i1 = i0 + 1;
i2 = i0 + xDim;
i3 = i0 + 1 + xDim;
x0 = buffer[i0];
x1 = buffer[i1];
x2 = buffer[i2];
x3 = buffer[i3];
if ((x0 > level) && (x1 > level) && (x2 > level) && (x3 > level)) {
zXMask.set(offset + i0, 0);
} else if ((x0 < level) && (x1 < level) && (x2 < level) && (x3 < level)) {
zXMask.set(offset + i0, 0);
} else {
zXMask.set(offset + i0, 255);
}
}
}
}
FileInfoBase[] fileInfo = zXMask.getFileInfo();
fileInfo[slice].setModality(srcImage.getFileInfo()[slice].getModality());
fileInfo[slice].setFileDirectory(srcImage.getFileInfo()[slice].getFileDirectory());
fileInfo[slice].setEndianess(srcImage.getFileInfo()[slice].getEndianess());
fileInfo[slice].setUnitsOfMeasure(srcImage.getFileInfo()[slice].getUnitsOfMeasure());
fileInfo[slice].setResolutions(srcImage.getFileInfo()[slice].getResolutions());
fileInfo[slice].setExtents(zXMask.getExtents());
fileInfo[slice].setMax(255);
fileInfo[slice].setMin(0);
fileInfo[slice].setPixelPadValue(srcImage.getFileInfo()[slice].getPixelPadValue());
fileInfo[slice].setPhotometric(srcImage.getFileInfo()[slice].getPhotometric());
}
