/**
* Calculates the approximate gradient magnitude for each pixel in a specified area and stores the
* result in a RealGrayImage pointer. parameters: x1 - the left bound of the specified area y1 -
* the right bottom bound of the specified area x2 - the right bound of the specified area y2 -
* the top bound of the specified area
*/
public RealGrayImage calcApproximateGradientMagnitude(int x1, int y1, int x2, int y2) {
IxImage = calcIx(x1, y1, x2, y2);
IyImage = calcIy(x1, y1, x2, y2);
int X = image.X();
int Y = image.Y();
double Iso = 0;
float Ix, Iy;
if (GradientMagnitude == null) GradientMagnitude = new RealGrayImage(X, Y);
for (int x = 0; x < X; x++) {
for (int y = 0; y < Y; y++) {
// calculate Iso
Ix = IxImage.get(x, y);
Iy = IyImage.get(x, y);
Iso = (Iy + Ix);
// put the result floato output image
GradientMagnitude.set(x, y, (float) Iso);
}
}
return GradientMagnitude;
}
/**
* Scales the range of <code>image</code> to an arbitrary min/max in a Region of Interest. The
* range used for all planes is the global max, min of the image.
*
* @param image RealColorImage to scale.
* @param roi Region of Interest of <code>image</code>.
* @return <code>image</code>.
*/
protected Image apply(RealColorImage image, ROI roi) {
RealGrayImage plane;
float min = image.min(roi);
float max = image.max(roi);
float r = 0;
float range = max - min;
float value = 0;
if (range == 0) range = 1; // to avoid divide by zero problems
for (int i = 0; i < 3; i++) {
plane = image.plane(i);
for (int y = roi.uy(); y <= roi.ly(); y++) {
for (int x = roi.ux(); x <= roi.lx(); x++) {
r = plane.get(x, y);
value = (((r - min) / (range) * (float_max - float_min)) + float_min);
plane.set(x, y, value);
}
}
image.setPlane(i, plane);
}
return image;
}
/**
* Calculates the gradient magnitude for each pixel in a specified area and stores the result in a
* RealGrayImage pointer. parameters: x1 - the left bound of the specified area y1 - the right
* bottom bound of the specified area x2 - the right bound of the specified area y2 - the top
* bound of the specified area
*/
public RealGrayImage calcGradientMagnitude(int x1, int y1, int x2, int y2) {
IxImage = calcIx(x1, y1, x2, y2);
IyImage = calcIy(x1, y1, x2, y2);
int X = image.X();
int Y = image.Y();
double Iso = 0;
float Ix, Iy;
if (GradientMagnitude == null) GradientMagnitude = new RealGrayImage(X, Y);
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
// calculate Iso
Ix = IxImage.get(x, y);
Iy = IyImage.get(x, y);
Iso = Math.sqrt((double) ((Iy * Iy) + (Ix * Ix)));
// put the result floato output image
GradientMagnitude.set(x, y, (float) Iso);
}
}
return GradientMagnitude;
}
/**
* Calculates the gradient phase for each pixel in a specified area and stores the result in a
* RealGrayImage pointer. parameters: x1 - the left bound of the specified area y1 - the right
* bottom bound of the specified area x2 - the right bound of the specified area y2 - the top
* bound of the specified area
*/
public RealGrayImage calcOrientationMap(int x1, int y1, int x2, int y2) {
IxImage = calcIx(x1, y1, x2, y2);
IyImage = calcIy(x1, y1, x2, y2);
int X = image.X();
int Y = image.Y();
double Iso = 0;
float Ix, Iy;
if (OrientationMap == null) OrientationMap = new RealGrayImage(X, Y);
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
// calculate Iso
Ix = IxImage.get(x, y);
Iy = IyImage.get(x, y);
Iso = Math.atan2(Iy, Ix);
// put the result floato output image
OrientationMap.set(x, y, (float) Iso);
}
}
return OrientationMap;
}
/**
* Overloaded methods to calculate Ix and the result is stored in the image pointed to by <code>
* dest</code>. The origin of <code>*dest</code> is (x1,y1) of image <code>*src</code>.
*/
public void calcIx(RealGrayImage src, RealGrayImage dest, int x1, int y1, int x2, int y2) {
// input image dimensions
int X = src.X();
int Y = src.Y();
// variables for calculating Isophote
// float c;
// float n;
float ne;
float e;
float se;
// float s;
float sw;
float w;
float nw;
float temp;
// calculate derivatives
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
// c = src.get(x, y);
// if (y - 1 > 0)
// n = src.get(x, y - 1);
// else
// n = 0;
if (y - 1 > 0 && x + 1 < X) ne = src.get(x + 1, y - 1);
else ne = 0;
if (x + 1 < X) e = src.get(x + 1, y);
else e = 0;
if (y + 1 < Y && x + 1 < X) se = src.get(x + 1, y + 1);
else se = 0;
// if (y + 1 < Y)
// s = src.get(x, y + 1);
// else
// s = 0;
if (x - 1 > 0 && y + 1 < Y) sw = src.get(x - 1, y + 1);
else sw = 0;
if (x - 1 > 0) w = src.get(x - 1, y);
else w = 0;
if (y - 1 > 0 && x - 1 > 0) nw = src.get(x - 1, y - 1);
else nw = 0;
// calculate Ix
temp = (float) ((-nw - 2.0 * w - sw + ne + 2.0 * e + se) / 8.0);
// put the result float to output image
dest.set(x - x1, y - y1, temp);
}
}
} // calcIx
/**
* Calculates Iyy (second derivative in the y direction) of the image in a specified area.
* parameters: x1 - the left bound of the specified area y1 - the right bottom bound of the
* specified area x2 - the right bound of the specified area y2 - the top bound of the specified
* area
*/
public RealGrayImage calcIyy(int x1, int y1, int x2, int y2) {
if (IyyImage == null) IyyImage = new RealGrayImage(image.X(), image.Y());
try {
ImageKernel ik = new ImageKernel(10); // D_YY
Convolve c = new Convolve(ik);
IyyImage = (RealGrayImage) c.apply((Image) image, new ROI(x1, y1, x2, y2));
IyyImage = IyyImage.divide(3f);
} catch (Exception e) {
}
return IyyImage;
}
/** isophote flow??? */
public RealGrayImage calcIsophoteFlowStore(int x1, int y1, int x2, int y2) {
IxImage = calcIx(x1, y1, x2, y2);
IyImage = calcIy(x1, y1, x2, y2);
IxxImage = calcIxx(x1, y1, x2, y2);
IyyImage = calcIyy(x1, y1, x2, y2);
IxyImage = calcIxy(x1, y1, x2, y2);
int X = image.X();
int Y = image.Y();
double Iso = 0;
float Ix, Iy, Ixx, Iyy, Ixy;
if (IsophoteCurvatureFlow == null) IsophoteCurvatureFlow = new RealGrayImage(X, Y);
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
// calculate Iso
Ix = IxImage.get(x, y);
Iy = IyImage.get(x, y);
Ixx = IxxImage.get(x, y);
Iyy = IyyImage.get(x, y);
Ixy = IxyImage.get(x, y);
Iso =
((Iy * Iy * Ixx) - (2 * Ix * Ixy * Iy) + (Iyy * Ix * Ix)) / (1 + (Ix * Ix) + (Iy * Iy));
// put the result float to output image
IsophoteCurvatureFlow.set(x, y, (float) Iso);
}
}
return IsophoteCurvatureFlow;
}
/**
* Calculate Iy (first derivative in the y direction) of the image in a specified area.
* parameters: x1 - the left bound of the specified area y1 - the right bottom bound of the
* specified area x2 - the right bound of the specified area y2 - the top bound of the specified
* area
*/
public RealGrayImage calcIy(int x1, int y1, int x2, int y2) {
if (IyImage == null) IyImage = new RealGrayImage(image.X(), image.Y());
try {
ImageKernel ik = new ImageKernel(2); // Sobel_Y
Convolve c = new Convolve(ik);
IyImage = (RealGrayImage) c.apply((Image) image, new ROI(x1, y1, x2, y2));
for (int x = x1; x < x2; x++)
for (int y = y1; y < y2; y++) IyImage.set(x, y, (float) (IyImage.get(x, y) / 8.0));
} catch (Exception e) {
}
return IyImage;
}
/**
* Calculates Ix (first derivative in the x direction) of the image in a specified area.
* parameters: x1 - the left bound of the specified area y1 - the right bottom bound of the
* specified area x2 - the right bound of the specified area y2 - the top bound of the specified
* area
*/
public RealGrayImage calcIx(int x1, int y1, int x2, int y2) {
if (IxImage == null) IxImage = new RealGrayImage(image.X(), image.Y());
try {
ImageKernel ik = new ImageKernel(1); // Sobel_X
Convolve c = new Convolve(ik);
ROI roi = new ROI(x1, y1, x2, y2);
IxImage = (RealGrayImage) c.apply((Image) image, roi); // x1, y1, x2,
// y2);
for (int x = x1; x < x2; x++)
for (int y = y1; y < y2; y++) IxImage.set(x, y, IxImage.get(x, y) / 8.0f);
} catch (Exception e) {
}
return IxImage;
}
/**
* Scales the range of <code>image</code> to an arbitrary min/max in a Region of Interest.
*
* @param image RealGrayImage to scale.
* @param roi Region of Interest of <code>image</code>.
* @return <code>image</code>.
*/
protected Image apply(RealGrayImage image, ROI roi) {
float min = image.min(roi);
float max = image.max(roi);
float r = 0;
float range = max - min;
if (range == 0)
range = 1; // to avoid divide by zero (r-min will be zero so value will always be float_min)
float value = 0;
for (int y = roi.uy(); y <= roi.ly(); y++) {
for (int x = roi.ux(); x <= roi.lx(); x++) {
r = (float) image.get(x, y);
value = ((float) ((r - min) / (range)) * (float_max - float_min)) + float_min;
image.set(x, y, (float) value);
}
}
return image;
}
/** Writes a RealGrayImage to a file, byteSizing first */
public void writeByteSized(RealGrayImage im) throws IOException {
X = im.X();
Y = im.Y();
// convert to byte size
RealGrayImage tmpim = (RealGrayImage) im.copy();
tmpim.byteSize();
// write PGM in raw format
writeRawPRGMHeader(X, Y);
for (int y = 0; y < Y; y++) {
for (int x = 0; x < X; x++) {
data.write((byte) tmpim.get(x, y));
}
}
}
/**
* Scales the range of <code>image</code> to an arbitrary min/max.
*
* @param image RealGrayImage to scale.
* @return <code>image</code>.
*/
protected Image apply(RealGrayImage image) {
return apply(image, new ROI(0, 0, image.X() - 1, image.Y() - 1));
}
/**
* This method caluculates the isophote curvature image in a specified area. This function is less
* memory floatensive than <i>calcIsophoteStore</i>. parameters: x1 - the left bound of the
* specified area y1 - the right bottom bound of the specified area x2 - the right bound of the
* specified area y2 - the top bound of the specified area
*/
public RealGrayImage calcIsophote(int x1, int y1, int x2, int y2) {
// check for null images
if (image == null) return null;
// input image dimensions
int X = image.X();
int Y = image.Y();
if (IsophoteCurvature == null) IsophoteCurvature = new RealGrayImage(X, Y);
// variables for calculating Isophote
float Iso;
float Ix;
float Iy;
float Ixx;
float Ixy;
float Iyy;
float c;
float n;
float ne;
float e;
float se;
float s;
float sw;
float w;
float nw;
// calculate derivatives
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
try {
c = image.get(x, y);
n = image.get(x, y - 1);
ne = image.get(x + 1, y - 1);
e = image.get(x + 1, y);
se = image.get(x + 1, y + 1);
s = image.get(x, y + 1);
sw = image.get(x - 1, y + 1);
w = image.get(x - 1, y);
nw = image.get(x - 1, y - 1);
// calculate Ix
Ix = (-w + e) / 2;
// calculate Iy
Iy = (-n + s) / 2;
// calculate Ixx
Ixx = w + (-2 * c) + e;
// calculate Iyy
Iyy = n + (-2 * c) + s;
// calculate Ixy
Ixy = (nw + -ne + -sw + se) / 4;
// calculate Iso
Iso =
(float)
(((Iy * Iy * Ixx) - (2 * Ix * Ixy * Iy) + (Iyy * Ix * Ix))
/ Math.sqrt(
(double)
(((Ix * Ix) + (Iy * Iy))
* ((Ix * Ix) + (Iy * Iy))
* ((Ix * Ix) + (Iy * Iy)))));
// put the result float to output image
IsophoteCurvature.set(x, y, Iso);
} catch (Exception ex) {
}
}
}
return IsophoteCurvature;
} // calcIsophote
/**
* This method caluculates the Isophote flow of a RealGrayImage image at the specified area. This
* function is less memory floatensive than <i>calcIsophoteFlowStore</i>
*/
public RealGrayImage calcIsophoteFlow(int x1, int y1, int x2, int y2) {
// check for null images
if (image == null) return null;
// input image dimensions
int X = image.X();
int Y = image.Y();
// variables for calculating Isophote
float Iso;
float Ix;
float Iy;
float Ixx;
float Ixy;
float Iyy;
float c;
float n;
float ne;
float e;
float se;
float s;
float sw;
float w;
float nw;
if (IsophoteCurvatureFlow == null) IsophoteCurvatureFlow = new RealGrayImage(X, Y);
// calculate derivatives
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
c = image.get(x, y);
if (y - 1 > 0) n = image.get(x, y - 1);
else n = 0;
if (y - 1 > 0 && x + 1 < X) ne = image.get(x + 1, y - 1);
else ne = 0;
if (x + 1 < X) e = image.get(x + 1, y);
else e = 0;
if (y + 1 < Y && x + 1 < X) se = image.get(x + 1, y + 1);
else se = 0;
if (y + 1 < Y) s = image.get(x, y + 1);
else s = 0;
if (x - 1 > 0 && y + 1 < Y) sw = image.get(x - 1, y + 1);
else sw = 0;
if (x - 1 > 0) w = image.get(x - 1, y);
else w = 0;
if (y - 1 > 0 && x - 1 > 0) nw = image.get(x - 1, y - 1);
else nw = 0;
// calculate Ix
Ix = (-w + e) / 2;
// calculate Iy
Iy = (-n + s) / 2;
// calculate Ixx
Ixx = w + (-2 * c) + e;
// calculate Iyy
Iyy = n + (-2 * c) + s;
// calculate Ixy
Ixy = (nw + -ne + -sw + se) / 4;
// calculate Iso
double temp =
((Iy * Iy * Ixx) - (2 * Ix * Ixy * Iy) + (Iyy * Ix * Ix))
/ (0.01 + (Ix * Ix) + (Iy * Iy));
Iso = (float) temp;
// put the result floato output image
IsophoteCurvatureFlow.set(x, y, Iso);
}
}
return IsophoteCurvatureFlow;
} // calcIsophote
/**
* Substitutes current image by another image in a specified rectangle area. parameters: x1 - the
* left bound of the specified area y1 - the right bottom bound of the specified area x2 - the
* right bound of the specified area y2 - the top bound of the specified area
*/
public void setImage(RealGrayImage im, int x1, int y1, int x2, int y2) {
for (int x = x1; x < x2; x++) for (int y = y1; y < y2; y++) image.set(x, y, im.get(x, y));
}
/**
* Overloaded function to stores the result in a RealGrayImage object pointed by <code>dest</code>
* .
*/
public void calcIsophoteFlow(
int x1, int y1, int x2, int y2, RealGrayImage src, RealGrayImage dest) {
// input image dimensions
int X = src.X();
int Y = src.Y();
// variables for calculating Isophote
float Iso;
float Ix;
float Iy;
float Ixx;
float Ixy;
float Iyy;
float c;
float n;
float ne;
float e;
float se;
float s;
float sw;
float w;
float nw;
// calculate derivatives
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
c = src.get(x, y);
if (y - 1 > 0) n = src.get(x, y - 1);
else n = 0;
if (y - 1 > 0 && x + 1 < X) ne = src.get(x + 1, y - 1);
else ne = 0;
if (x + 1 < X) e = src.get(x + 1, y);
else e = 0;
if (y + 1 < Y && x + 1 < X) se = src.get(x + 1, y + 1);
else se = 0;
if (y + 1 < Y) s = src.get(x, y + 1);
else s = 0;
if (x - 1 > 0 && y + 1 < Y) sw = src.get(x - 1, y + 1);
else sw = 0;
if (x - 1 > 0) w = src.get(x - 1, y);
else w = 0;
if (y - 1 > 0 && x - 1 > 0) nw = src.get(x - 1, y - 1);
else nw = 0;
// calculate Ix
Ix = (-w + e) / 2;
// calculate Iy
Iy = (-n + s) / 2;
// calculate Ixx
Ixx = w + (-2 * c) + e;
// calculate Iyy
Iyy = n + (-2 * c) + s;
// calculate Ixy
Ixy = (nw + -ne + -sw + se) / 4;
// calculate Iso
double temp =
((Iy * Iy * Ixx) - (2 * Ix * Ixy * Iy) + (Iyy * Ix * Ix))
/ (0.1 + (Ix * Ix) + (Iy * Iy)); // why 0.1????
Iso = (float) temp;
// put the result float to output image
dest.set(x - x1, y - y1, Iso);
}
}
} // calcIsophote
/**
* Overloaded function to stores the result in a RealGrayImage object pointed by <code>dest</code>
* .
*/
public void calcIsophoteCurvature(
int x1, int y1, int x2, int y2, RealGrayImage src, RealGrayImage dest) {
double totalPix = 0;
double totalSquare = 0;
double totalAbsKappa = 0;
// double totalQuad = 0;
// input image dimensions
int X = src.X();
int Y = src.Y();
// variables for calculating Isophote
float Iso;
float Ix;
float Iy;
float Ixx;
float Ixy;
float Iyy;
float c;
float n;
float ne;
float e;
float se;
float s;
float sw;
float w;
float nw;
// calculate derivatives
for (int x = x1; x < x2; x++) {
for (int y = y1; y < y2; y++) {
c = src.get(x, y);
if (y - 1 > 0) n = src.get(x, y - 1);
else n = 0;
if (y - 1 > 0 && x + 1 < X) ne = src.get(x + 1, y - 1);
else ne = 0;
if (x + 1 < X) e = src.get(x + 1, y);
else e = 0;
if (y + 1 < Y && x + 1 < X) se = src.get(x + 1, y + 1);
else se = 0;
if (y + 1 < Y) s = src.get(x, y + 1);
else s = 0;
if (x - 1 > 0 && y + 1 < Y) sw = src.get(x - 1, y + 1);
else sw = 0;
if (x - 1 > 0) w = src.get(x - 1, y);
else w = 0;
if (y - 1 > 0 && x - 1 > 0) nw = src.get(x - 1, y - 1);
else nw = 0;
// calculate Ix
Ix = (-w + e) / 2;
// calculate Iy
Iy = (-n + s) / 2;
// calculate Ixx
Ixx = w + (-2 * c) + e;
// calculate Iyy
Iyy = n + (-2 * c) + s;
// calculate Ixy
Ixy = (nw + -ne + -sw + se) / 4;
// calculate Iso
double temp =
((Iy * Iy * Ixx) - (2 * Ix * Ixy * Iy) + (Iyy * Ix * Ix))
/ (1e-0 + Math.pow((Ix * Ix) + (Iy * Iy), 1.5));
Iso = (float) temp;
// put the result float to output image
dest.set(x - x1, y - y1, Iso);
totalAbsKappa += (float) Math.abs(Iso);
totalSquare += Iso * Iso;
// totalQuad += totalSquare*totalSquare;
totalPix++;
}
}
avgKappaSquare = totalSquare / totalPix;
avgAbsKappa = totalAbsKappa / totalPix;
stdDevAbsKappa = Math.sqrt(avgKappaSquare - (avgAbsKappa * avgAbsKappa));
// stdDevKappaSquare = sqrt((totalQuad/totalPix) - avgKappaSquare);
} // calcIsophote
