我正在创建一个小程序,它可以在大图像中检测对象(小图像),我正在使用OpenCV Java。由于需要考虑旋转和缩放,我使用了FeatureDetector.BRISK和DescriptorExtractor.BRISK。
以下方法用于过滤匹配结果以仅获取最佳匹配项。
我有两个问题:
以下方法用于过滤匹配结果以仅获取最佳匹配项。
我有两个问题:
- 是否有办法通过我所使用的循环来找到下面的min_dist和max_dist?
- 最重要的问题 - 现在问题是我需要使用这些匹配项来确定是否已找到对象(模板)。如果有人能在这里帮助我就太好了。
FeatureDetector fd = FeatureDetector.create(FeatureDetector.BRISK);
final MatOfKeyPoint keyPointsLarge = new MatOfKeyPoint();
final MatOfKeyPoint keyPointsSmall = new MatOfKeyPoint();
fd.detect(largeImage, keyPointsLarge);
fd.detect(smallImage, keyPointsSmall);
System.out.println("keyPoints.size() : "+keyPointsLarge.size());
System.out.println("keyPoints2.size() : "+keyPointsSmall.size());
Mat descriptorsLarge = new Mat();
Mat descriptorsSmall = new Mat();
DescriptorExtractor extractor = DescriptorExtractor.create(DescriptorExtractor.BRISK);
extractor.compute(largeImage, keyPointsLarge, descriptorsLarge);
extractor.compute(smallImage, keyPointsSmall, descriptorsSmall);
System.out.println("descriptorsA.size() : "+descriptorsLarge.size());
System.out.println("descriptorsB.size() : "+descriptorsSmall.size());
MatOfDMatch matches = new MatOfDMatch();
DescriptorMatcher matcher = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE_HAMMINGLUT);
matcher.match(descriptorsLarge, descriptorsSmall, matches);
System.out.println("matches.size() : "+matches.size());
MatOfDMatch matchesFiltered = new MatOfDMatch();
List<DMatch> matchesList = matches.toList();
List<DMatch> bestMatches= new ArrayList<DMatch>();
Double max_dist = 0.0;
Double min_dist = 100.0;
for (int i = 0; i < matchesList.size(); i++)
{
Double dist = (double) matchesList.get(i).distance;
if (dist < min_dist && dist != 0)
{
min_dist = dist;
}
if (dist > max_dist)
{
max_dist = dist;
}
}
System.out.println("max_dist : "+max_dist);
System.out.println("min_dist : "+min_dist);
double threshold = 3 * min_dist;
double threshold2 = 2 * min_dist;
if (threshold2 >= max_dist)
{
threshold = min_dist * 1.1;
}
else if (threshold >= max_dist)
{
threshold = threshold2 * 1.4;
}
System.out.println("Threshold : "+threshold);
for (int i = 0; i < matchesList.size(); i++)
{
Double dist = (double) matchesList.get(i).distance;
System.out.println(String.format(i + " match distance best : %s", dist));
if (dist < threshold)
{
bestMatches.add(matches.toList().get(i));
System.out.println(String.format(i + " best match added : %s", dist));
}
}
matchesFiltered.fromList(bestMatches);
System.out.println("matchesFiltered.size() : " + matchesFiltered.size());
编辑
我按照以下方式编辑了我的代码。我知道仅根据最佳匹配数量来判断是否找到对象还不是最好的方法。请分享您的看法。
System.out.println("max_dist : "+max_dist);
System.out.println("min_dist : "+min_dist);
if(min_dist > 50 )
{
System.out.println("No match found");
System.out.println("Just return ");
return false;
}
double threshold = 3 * min_dist;
double threshold2 = 2 * min_dist;
if (threshold > 75)
{
threshold = 75;
}
else if (threshold2 >= max_dist)
{
threshold = min_dist * 1.1;
}
else if (threshold >= max_dist)
{
threshold = threshold2 * 1.4;
}
System.out.println("Threshold : "+threshold);
for (int i = 0; i < matchesList.size(); i++)
{
Double dist = (double) matchesList.get(i).distance;
if (dist < threshold)
{
bestMatches.add(matches.toList().get(i));
//System.out.println(String.format(i + " best match added : %s", dist));
}
}
matchesFiltered.fromList(bestMatches);
System.out.println("matchesFiltered.size() : " + matchesFiltered.size());
if(matchesFiltered.rows() >= 1)
{
System.out.println("match found");
return true;
}
else
{
return false;
}