boofcv.alg.template.TemplateNCC Maven / Gradle / Ivy
/*
* Copyright (c) 2021, Peter Abeles. All Rights Reserved.
*
* This file is part of BoofCV (http://boofcv.org).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package boofcv.alg.template;
import boofcv.struct.image.GrayF32;
import boofcv.struct.image.GrayU8;
import boofcv.struct.image.ImageBase;
import org.ejml.UtilEjml;
import java.util.Objects;
/**
* Template matching which uses normalized cross correlation (NCC).
*
* @author Peter Abeles
*/
@SuppressWarnings("NullAway.Init")
public abstract class TemplateNCC>
implements TemplateIntensityImage.EvaluatorMethod {
// used to avoid divide by zero
float EPS = UtilEjml.F_EPS;
TemplateIntensityImage o;
@Override
public void initialize( TemplateIntensityImage owner ) {
this.o = owner;
setupTemplate(o.template);
}
@Override
public boolean isMaximize() {
return true;
}
/**
* Precompres template statistics here
*/
public abstract void setupTemplate( T template );
public static class F32 extends TemplateNCC {
float area;
float templateMean;
float templateSigma;
@Override
public float evaluate( int tl_x, int tl_y ) {
float top = 0;
float imageMean = 0;
float imageSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
for (int x = 0; x < o.template.width; x++) {
imageMean += o.image.data[imageIndex++];
}
}
imageMean /= area;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
final float templateVal = o.template.data[templateIndex++];
final float imageVal = o.image.data[imageIndex++];
float imageDiff = imageVal - imageMean;
imageSigma += imageDiff*imageDiff;
top += imageDiff*(templateVal - templateMean);
}
}
imageSigma = (float)Math.sqrt(imageSigma);
return top/(EPS + imageSigma*templateSigma);
}
@Override
public float evaluateMask( int tl_x, int tl_y ) {
Objects.requireNonNull(o.mask);
float top = 0;
float imageMean = 0;
float imageSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
for (int x = 0; x < o.template.width; x++) {
imageMean += o.image.data[imageIndex++];
}
}
imageMean /= area;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
int templateIndex = o.template.startIndex + y*o.template.stride;
int maskIndex = o.mask.startIndex + y*o.mask.stride;
for (int x = 0; x < o.template.width; x++) {
final float templateVal = o.template.data[templateIndex++];
final float imageVal = o.image.data[imageIndex++];
float imageDiff = imageVal - imageMean;
imageSigma += imageDiff*imageDiff;
top += o.mask.data[maskIndex++]*imageDiff*(templateVal - templateMean);
}
}
imageSigma = (float)Math.sqrt(imageSigma);
return top/(EPS + imageSigma*templateSigma);
}
@Override
public void setupTemplate( GrayF32 template ) {
area = o.template.width*o.template.height;
templateMean = 0;
for (int y = 0; y < o.template.height; y++) {
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
templateMean += o.template.data[templateIndex++];
}
}
templateMean /= area;
templateSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
float diff = o.template.data[templateIndex++] - templateMean;
templateSigma += diff*diff;
}
}
templateSigma = (float)Math.sqrt(templateSigma);
}
}
public static class U8 extends TemplateNCC {
float area;
float templateMean;
float templateSigma;
@Override
public float evaluate( int tl_x, int tl_y ) {
float top = 0;
int imageSum = 0;
float imageSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
for (int x = 0; x < o.template.width; x++) {
imageSum += o.image.data[imageIndex++] & 0xFF;
}
}
float imageMean = imageSum/area;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
final int templateVal = o.template.data[templateIndex++] & 0xFF;
final int imageVal = o.image.data[imageIndex++] & 0xFF;
float imageDiff = imageVal - imageMean;
imageSigma += imageDiff*imageDiff;
top += imageDiff*(templateVal - templateMean);
}
}
imageSigma = (float)Math.sqrt(imageSigma);
return top/(EPS + imageSigma*templateSigma);
}
@Override
public float evaluateMask( int tl_x, int tl_y ) {
Objects.requireNonNull(o.mask);
float top = 0;
int imageSum = 0;
float imageSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
for (int x = 0; x < o.template.width; x++) {
imageSum += o.image.data[imageIndex++] & 0xFF;
}
}
float imageMean = imageSum/area;
for (int y = 0; y < o.template.height; y++) {
int imageIndex = o.image.startIndex + (tl_y + y)*o.image.stride + tl_x;
int templateIndex = o.template.startIndex + y*o.template.stride;
int maskIndex = o.mask.startIndex + y*o.mask.stride;
for (int x = 0; x < o.template.width; x++) {
final int templateVal = o.template.data[templateIndex++] & 0xFF;
final int imageVal = o.image.data[imageIndex++] & 0xFF;
final int m = o.mask.data[maskIndex++] & 0xFF;
float imageDiff = imageVal - imageMean;
imageSigma += imageDiff*imageDiff;
top += m*imageDiff*(templateVal - templateMean);
}
}
imageSigma = (float)Math.sqrt(imageSigma);
return top/(EPS + imageSigma*templateSigma);
}
@Override
public void setupTemplate( GrayU8 template ) {
area = o.template.width*o.template.height;
templateMean = 0;
for (int y = 0; y < o.template.height; y++) {
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
templateMean += o.template.data[templateIndex++] & 0xFF;
}
}
templateMean /= area;
templateSigma = 0;
for (int y = 0; y < o.template.height; y++) {
int templateIndex = o.template.startIndex + y*o.template.stride;
for (int x = 0; x < o.template.width; x++) {
float diff = (o.template.data[templateIndex++] & 0xFF) - templateMean;
templateSigma += diff*diff;
}
}
templateSigma = (float)Math.sqrt(templateSigma);
}
}
@Override
public boolean isBorderProcessed() {
return false;
}
}