/**
* Constructs a TemplateMatcher object. If a mask shape is specified, then only pixels that are
* entirely inside the mask are included in the template.
*
* @param image the image to match
* @param maskShape a shape to define inside pixels (may be null)
*/
public TemplateMatcher(BufferedImage image, Shape maskShape) {
original = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
original.createGraphics().drawImage(image, 0, 0, null);
mask = maskShape;
getTemplate();
// set up the Gaussian curve fitter
dataset = new Dataset();
fitter = new DatasetCurveFitter(dataset);
fitter.setAutofit(true);
f = new UserFunction("gaussian"); // $NON-NLS-1$
f.setParameters(
new String[] {"a", "b", "c"}, // $NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
new double[] {1, 0, 1});
f.setExpression("a*exp(-(x-b)^2/c)", new String[] {"x"}); // $NON-NLS-1$ //$NON-NLS-2$
}
/**
* Gets the template location at which the best match occurs in a rectangle and along a line. May
* return null.
*
* @param target the image to search
* @param searchRect the rectangle to search within the target image
* @param x0 the x-component of a point on the line
* @param y0 the y-component of a point on the line
* @param slope the slope of the line
* @param spread the spread of the line (line width = 1+2*spread)
* @return the optimized template location of the best match, if any
*/
public TPoint getMatchLocation(
BufferedImage target, Rectangle searchRect, double x0, double y0, double theta, int spread) {
wTarget = target.getWidth();
hTarget = target.getHeight();
// determine insets needed to accommodate template
int left = wTemplate / 2, right = left;
if (wTemplate % 2 > 0) right++;
int top = hTemplate / 2, bottom = top;
if (hTemplate % 2 > 0) bottom++;
// trim search rectangle if necessary
searchRect.x = Math.max(left, Math.min(wTarget - right, searchRect.x));
searchRect.y = Math.max(top, Math.min(hTarget - bottom, searchRect.y));
searchRect.width = Math.min(wTarget - searchRect.x - right, searchRect.width);
searchRect.height = Math.min(hTarget - searchRect.y - bottom, searchRect.height);
if (searchRect.width <= 0 || searchRect.height <= 0) {
peakHeight = Double.NaN;
peakWidth = Double.NaN;
return null;
}
// set up test pixels to search (rectangle plus template)
int xMin = Math.max(0, searchRect.x - left);
int xMax = Math.min(wTarget, searchRect.x + searchRect.width + right);
int yMin = Math.max(0, searchRect.y - top);
int yMax = Math.min(hTarget, searchRect.y + searchRect.height + bottom);
wTest = xMax - xMin;
hTest = yMax - yMin;
if (target.getType() != BufferedImage.TYPE_INT_RGB) {
BufferedImage image = new BufferedImage(wTarget, hTarget, BufferedImage.TYPE_INT_RGB);
image.createGraphics().drawImage(target, 0, 0, null);
target = image;
}
targetPixels = new int[wTest * hTest];
target.getRaster().getDataElements(xMin, yMin, wTest, hTest, targetPixels);
// get the points to search along the line
ArrayList<Point2D> searchPts = getSearchPoints(searchRect, x0, y0, theta);
if (searchPts == null) {
peakHeight = Double.NaN;
peakWidth = Double.NaN;
return null;
}
// collect differences in a map as they are measured
HashMap<Point2D, Double> diffs = new HashMap<Point2D, Double>();
// find the point with the minimum difference from template
double matchDiff = largeNumber; // larger than typical differences
int xMatch = 0, yMatch = 0;
double avgDiff = 0;
Point2D matchPt = null;
for (Point2D pt : searchPts) {
int x = (int) pt.getX();
int y = (int) pt.getY();
double diff = getDifferenceAtTestPoint(x, y);
diffs.put(pt, diff);
avgDiff += diff;
if (diff < matchDiff) {
matchDiff = diff;
xMatch = x;
yMatch = y;
matchPt = pt;
}
}
avgDiff /= searchPts.size();
peakHeight = avgDiff / matchDiff - 1;
peakWidth = Double.NaN;
double dl = 0;
int matchIndex = searchPts.indexOf(matchPt);
// if match is not exact, fit a Gaussian and find peak
if (!Double.isInfinite(peakHeight) && matchIndex > 0 && matchIndex < searchPts.size() - 1) {
// fill data arrays
Point2D pt = searchPts.get(matchIndex - 1);
double diff = diffs.get(pt);
xValues[0] = -pt.distance(matchPt);
yValues[0] = avgDiff / diff - 1;
xValues[1] = 0;
yValues[1] = peakHeight;
pt = searchPts.get(matchIndex + 1);
diff = diffs.get(pt);
xValues[2] = pt.distance(matchPt);
yValues[2] = avgDiff / diff - 1;
// determine approximate offset (dl) and width (w) values
double pull = -xValues[0] / (yValues[1] - yValues[0]);
double push = xValues[2] / (yValues[1] - yValues[2]);
if (Double.isNaN(pull)) pull = LARGE_NUMBER;
if (Double.isNaN(push)) push = LARGE_NUMBER;
dl = 0.3 * (xValues[2] - xValues[0]) * (push - pull) / (push + pull);
double ratio = dl > 0 ? peakHeight / yValues[0] : peakHeight / yValues[2];
double w = dl > 0 ? dl - xValues[0] : dl - xValues[2];
w = w * w / Math.log(ratio);
// set parameters and fit to x data
dataset.clear();
dataset.append(xValues, yValues);
double rmsDev = 1;
for (int k = 0; k < 3; k++) {
double c = k == 0 ? w : k == 1 ? w / 3 : w * 3;
f.setParameterValue(0, peakHeight);
f.setParameterValue(1, dl);
f.setParameterValue(2, c);
rmsDev = fitter.fit(f);
if (rmsDev < 0.01) { // fitter succeeded (3-point fit should be exact)
dl = f.getParameterValue(1);
peakWidth = f.getParameterValue(2);
break;
}
}
}
double dx = dl * Math.cos(theta);
double dy = dl * Math.sin(theta);
double xImage = xMatch + searchRect.x - left - trimLeft + dx;
double yImage = yMatch + searchRect.y - top - trimTop + dy;
return new TPoint(xImage, yImage);
}
/**
* Gets the template location at which the best match occurs in a rectangle. May return null.
*
* @param target the image to search
* @param searchRect the rectangle to search within the target image
* @return the optimized template location at which the best match, if any, is found
*/
public TPoint getMatchLocation(BufferedImage target, Rectangle searchRect) {
wTarget = target.getWidth();
hTarget = target.getHeight();
// determine insets needed to accommodate template
int left = wTemplate / 2, right = left;
if (wTemplate % 2 > 0) right++;
int top = hTemplate / 2, bottom = top;
if (hTemplate % 2 > 0) bottom++;
// trim search rectangle if necessary
searchRect.x = Math.max(left, Math.min(wTarget - right, searchRect.x));
searchRect.y = Math.max(top, Math.min(hTarget - bottom, searchRect.y));
searchRect.width = Math.min(wTarget - searchRect.x - right, searchRect.width);
searchRect.height = Math.min(hTarget - searchRect.y - bottom, searchRect.height);
if (searchRect.width <= 0 || searchRect.height <= 0) {
peakHeight = Double.NaN;
peakWidth = Double.NaN;
return null;
}
// set up test pixels to search (rectangle plus template)
int xMin = Math.max(0, searchRect.x - left);
int xMax = Math.min(wTarget, searchRect.x + searchRect.width + right);
int yMin = Math.max(0, searchRect.y - top);
int yMax = Math.min(hTarget, searchRect.y + searchRect.height + bottom);
wTest = xMax - xMin;
hTest = yMax - yMin;
if (target.getType() != BufferedImage.TYPE_INT_RGB) {
BufferedImage image = new BufferedImage(wTarget, hTarget, BufferedImage.TYPE_INT_RGB);
image.createGraphics().drawImage(target, 0, 0, null);
target = image;
}
targetPixels = new int[wTest * hTest];
target.getRaster().getDataElements(xMin, yMin, wTest, hTest, targetPixels);
// find the rectangle point with the minimum difference
double matchDiff = largeNumber; // larger than typical differences
int xMatch = 0, yMatch = 0;
double avgDiff = 0;
for (int x = 0; x <= searchRect.width; x++) {
for (int y = 0; y <= searchRect.height; y++) {
double diff = getDifferenceAtTestPoint(x, y);
avgDiff += diff;
if (diff < matchDiff) {
matchDiff = diff;
xMatch = x;
yMatch = y;
}
}
}
avgDiff /= (searchRect.width * searchRect.height);
peakHeight = avgDiff / matchDiff - 1;
peakWidth = Double.NaN;
double dx = 0, dy = 0;
// if match is not exact, fit a Gaussian and find peak
if (!Double.isInfinite(peakHeight)) {
// fill data arrays
xValues[1] = yValues[1] = peakHeight;
for (int i = -1; i < 2; i++) {
if (i == 0) continue;
double diff = getDifferenceAtTestPoint(xMatch + i, yMatch);
xValues[i + 1] = avgDiff / diff - 1;
diff = getDifferenceAtTestPoint(xMatch, yMatch + i);
yValues[i + 1] = avgDiff / diff - 1;
}
// estimate peakHeight = peak of gaussian
// estimate offset dx of gaussian
double pull = 1 / (xValues[1] - xValues[0]);
double push = 1 / (xValues[1] - xValues[2]);
if (Double.isNaN(pull)) pull = LARGE_NUMBER;
if (Double.isNaN(push)) push = LARGE_NUMBER;
dx = 0.6 * (push - pull) / (push + pull);
// estimate width wx of gaussian
double ratio = dx > 0 ? peakHeight / xValues[0] : peakHeight / xValues[2];
double wx = dx > 0 ? dx + 1 : dx - 1;
wx = wx * wx / Math.log(ratio);
// estimate offset dy of gaussian
pull = 1 / (yValues[1] - yValues[0]);
push = 1 / (yValues[1] - yValues[2]);
if (Double.isNaN(pull)) pull = LARGE_NUMBER;
if (Double.isNaN(push)) push = LARGE_NUMBER;
dy = 0.6 * (push - pull) / (push + pull);
// estimate width wy of gaussian
ratio = dy > 0 ? peakHeight / yValues[0] : peakHeight / yValues[2];
double wy = dy > 0 ? dy + 1 : dy - 1;
wy = wy * wy / Math.log(ratio);
// set x parameters and fit to x data
dataset.clear();
dataset.append(pixelOffsets, xValues);
double rmsDev = 1;
for (int k = 0; k < 3; k++) {
double c = k == 0 ? wx : k == 1 ? wx / 3 : wx * 3;
f.setParameterValue(0, peakHeight);
f.setParameterValue(1, dx);
f.setParameterValue(2, c);
rmsDev = fitter.fit(f);
if (rmsDev < 0.01) { // fitter succeeded (3-point fit should be exact)
dx = f.getParameterValue(1);
peakWidth = f.getParameterValue(2);
break;
}
}
if (!Double.isNaN(peakWidth)) {
// set y parameters and fit to y data
dataset.clear();
dataset.append(pixelOffsets, yValues);
for (int k = 0; k < 3; k++) {
double c = k == 0 ? wy : k == 1 ? wy / 3 : wy * 3;
f.setParameterValue(0, peakHeight);
f.setParameterValue(1, dx);
f.setParameterValue(2, c);
rmsDev = fitter.fit(f);
if (rmsDev < 0.01) { // fitter succeeded (3-point fit should be exact)
dy = f.getParameterValue(1);
peakWidth = (peakWidth + f.getParameterValue(2)) / 2;
break;
}
}
if (rmsDev > 0.01) peakWidth = Double.NaN;
}
}
double xImage = xMatch + searchRect.x - left - trimLeft + dx;
double yImage = yMatch + searchRect.y - top - trimTop + dy;
return new TPoint(xImage, yImage);
}
