我正在创建一个小程序来检测大图像中的对象（小图像），我正在使用 OpenCV java。由于我必须考虑旋转和缩放，我使用了 FeatureDetector.BRISK 和 DescriptorExtractor.BRISK。
以下方法用于过滤匹配结果以仅获得最佳匹配。
我有两个问题
- 有没有办法用我用过的循环找到下面的 min_dist 和 max_dist ？
- 最重要的问题 - 现在的问题是我需要使用这些匹配来确定是否找到了对象（模板）。如果有人在这里帮助我，那就太好了。
提前致谢。
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
编辑我的代码如下。我知道这仍然不是根据没有最佳匹配来得出是否找到对象的最佳方法。所以请分享你的观点。
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;
}