我能够检测图像中最大的正方形/矩形(绿色)。但是,我想将图像中检测到的最大正方形/矩形转换为新图像(存储在新的 Mat 中)。
这是该函数的返回图像,其上有最大的矩形/正方形:http://img153.imageshack.us/img153/9308/nn4w.png http://img153.imageshack.us/img153/9308/nn4w.png
到目前为止,这是我的代码:
private Mat findLargestRectangle(Mat original_image) {
Mat imgSource = original_image;
//convert the image to black and white
Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BGR2GRAY);
//convert the image to black and white does (8 bit)
Imgproc.Canny(imgSource, imgSource, 50, 50);
//apply gaussian blur to smoothen lines of dots
Imgproc.GaussianBlur(imgSource, imgSource, new Size(5, 5), 5);
//find the contours
List<MatOfPoint> contours = new ArrayList<MatOfPoint>();
Imgproc.findContours(imgSource, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE);
double maxArea = -1;
int maxAreaIdx = -1;
MatOfPoint temp_contour = contours.get(0); //the largest is at the index 0 for starting point
MatOfPoint2f approxCurve = new MatOfPoint2f();
Mat largest_contour = contours.get(0);
List<MatOfPoint> largest_contours = new ArrayList<MatOfPoint>();
for (int idx = 0; idx < contours.size(); idx++) {
temp_contour = contours.get(idx);
double contourarea = Imgproc.contourArea(temp_contour);
//compare this contour to the previous largest contour found
if (contourarea > maxArea) {
//check if this contour is a square
MatOfPoint2f new_mat = new MatOfPoint2f( temp_contour.toArray() );
int contourSize = (int)temp_contour.total();
Imgproc.approxPolyDP(new_mat, approxCurve, contourSize*0.05, true);
if (approxCurve.total() == 4) {
maxArea = contourarea;
maxAreaIdx = idx;
largest_contours.add(temp_contour);
largest_contour = temp_contour;
}
}
}
MatOfPoint temp_largest = largest_contours.get(largest_contours.size()-1);
largest_contours = new ArrayList<MatOfPoint>();
largest_contours.add(temp_largest);
Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BayerBG2RGB);
Imgproc.drawContours(imgSource, largest_contours, -1, new Scalar(0, 255, 0), 1);
//create the new image here using the largest detected square
Toast.makeText(getApplicationContext(), "Largest Contour: ", Toast.LENGTH_LONG).show();
return imgSource;
}
变量最大轮廓是一个 MatOfPoint 列表,但只包含最大的轮廓,也存储在最大轮廓多变的。如何根据最大轮廓制作新图像?
我在 Android 中使用 OpenCV,几乎没有关于检测图像的教程,但不完全是关于如何使用 Imgproc.warpPerspective()
Thanks!