opencv两张图片找不同

var path = "测试图片.png";
var img = images.read(path);
path = "测试图片有绿圈.png";
var img2 = images.read(path);

let src1Mat = img.getMat();
let src2Mat = img2.getMat();

let src1MatGray = new Mat();
let src2MatGray = new Mat();
Imgproc.cvtColor(src1Mat, src1MatGray, Imgproc.COLOR_BGR2GRAY);
Imgproc.cvtColor(src2Mat, src2MatGray, Imgproc.COLOR_BGR2GRAY);

var dst = new Mat();
Core.subtract(src2MatGray, src1MatGray, dst);

var subtractImg = images.matToImage(dst);
let subtractImgPath = files.join(files.getSdcardPath(), "图片减法.png");
images.save(subtractImg, subtractImgPath);

let 高斯滤波后的图像 = new Mat();
Imgproc.GaussianBlur(dst, 高斯滤波后的图像, newSize(5), 3, 3);

let 闭运算后的图像 = new Mat();
Imgproc.morphologyEx(
  高斯滤波后的图像,
  闭运算后的图像,
  Imgproc.MORPH_CLOSE,
  Imgproc.getStructuringElement(Imgproc.MORPH_RECT, newSize(5))
);

let contours = new java.util.ArrayList();
let hierarchy = new Mat();
Imgproc.findContours(闭运算后的图像, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

let bigArr = [];
let cxyArr = [];
let areaArr = [];
for (let i = 0; i < contours.size(); ++i) {
  let item = contours.get(i);
  // 最小外接矩形
  let rotateRect = Imgproc.minAreaRect(new MatOfPoint2f(item.toArray()));
  // 矩形中心
  cxyArr.push([rotateRect.center.x, rotateRect.center.y]);
  // 轮廓面积
  let area = Math.abs(Imgproc.contourArea(item));
  areaArr.push(area);
  var len = item.size();
  let arr = [];
  // 提取轮廓坐标
  for (var w = 0; w < len.width; w++) {
    for (var h = 0; h < len.height; h++) {
      arr.push(item.get(h, w));
    }
  }
  bigArr.push(arr);
}

var len = bigArr.length;
for (var i = 0; i < len; i++) {
  if (areaArr[i] < 10000) {
    continue;
  }
  let arr = bigArr[i];
  var arrLen = arr.length;
  path.moveTo(arr[0][0], arr[0][1]);
  for (var j = 1; j < arrLen; j++) {
    path.lineTo(arr[j][0], arr[j][1]);
  }
  path.close();
  // 画轮廓
  canvas.drawPath(path, paint);
  // 画轮廓中心
  let xy = cxyArr[i];
  canvas.drawPoint(xy[0], xy[1], paint);
}

var image = canvas.toImage();
images.save(image, "/sdcard/tmp.png");

img.recycle();
img2.recycle();
subtractImg.recycle();
image.recycle();
src1Mat.release();
src2Mat.release();
src1MatGray.release();
src2MatGray.release();
dst.release();
高斯滤波后的图像.release();
闭运算后的图像.release();
hierarchy.release();

app.viewFile("/sdcard/tmp.png");

Core.absdiff(src2MatGray, src1MatGray, dst);

findContours( InputOutputArray image, OutputArrayOfArrays contours,
                              OutputArray hierarchy, int mode,
                              int method, Point offset=Point());
取值一：CV_RETR_EXTERNAL只检测最外围轮廓，包含在外围轮廓内的内围轮廓被忽略
取值一：CV_CHAIN_APPROX_NONE 保存物体边界上所有连续的轮廓点到contours向量内
取值二：CV_CHAIN_APPROX_SIMPLE 仅保存轮廓的拐点信息

color = new Scalar(0,255,0)
color = new Scalar(199);

Imgproc.drawContours(闭运算后的图像, contours, idx, color, Core.FILLED, 8, hierarchy);