OpenCV的+安卓+号牌识别(OpenCV + Android + 图像水平矫正)

最新推荐文章于 2024-06-03 20:34:48 发布

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最新推荐文章于 2024-06-03 20:34:48 发布

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CC 4.0 BY-SA版权

文章标签：人工智能移动开发

原文链接：https://yq.aliyun.com/articles/595082

本文介绍了一种基于图像处理的价签矫正算法。该算法通过轮廓检测实现，首先将输入图片转换为灰度图像并进行阈值处理，然后寻找轮廓并筛选出符合条件的矩形区域，对选定区域进行最小外接矩形计算并根据角度进行旋转矫正，最终保存矫正后的图像。

/**
 * 价签矫正
 */
public void getContouresPic (Bitmap source) {
    Mat imageSobleOutThreshold = new Mat();

    Mat gray = new Mat();
    Utils.bitmapToMat(source, imageSobleOutThreshold);
    Imgproc.cvtColor(imageSobleOutThreshold, imageSobleOutThreshold, Imgproc.COLOR_BGR2GRAY);

    Imgproc.threshold(imageSobleOutThreshold, gray, 125, 225, Imgproc.THRESH_BINARY);//maxVal就是控制黑白反转的,0是黑

    //Utils.matToBitmap(gray, source);
    
    ArrayList<RotatedRect> rects = new  ArrayList<RotatedRect>();
    ArrayList<MatOfPoint> contours = new ArrayList<MatOfPoint>();
    Imgproc.findContours(gray, contours, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_NONE);


    for(int i=0;i<contours.size();i++){
        Rect rect = Imgproc.boundingRect(contours.get(i));
        if (rect.width > 500 && rect.width/rect.height == 1) {
            MatOfPoint2f mp2f = new MatOfPoint2f(contours.get(i).toArray());
            RotatedRect mr = Imgproc.minAreaRect(mp2f);

            double area = Math.abs(Imgproc.contourArea(mp2f));

            double angle = mr.angle+90;

            Mat ratationedImg = new Mat(gray.rows(), gray.cols(), CvType.CV_8UC3);
            ratationedImg.setTo(new Scalar(0, 0, 0));



            Point center = mr.center;//中心点
            Mat m2 = Imgproc.getRotationMatrix2D(center, angle, 1);
            Imgproc.warpAffine(imageSobleOutThreshold, ratationedImg, m2, imageSobleOutThreshold.size(), 1, 0, new Scalar(0) );//仿射变换


            Utils.matToBitmap(ratationedImg, source);

            
            File file = new File(Environment.getExternalStorageDirectory()+"/AiLingGong/", "ll"+System.currentTimeMillis()+".jpg");
            try {
                FileOutputStream out = new FileOutputStream(file);
                source.compress(Bitmap.CompressFormat.JPEG, 100, out);
                out.flush();
                out.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            Log.d("----------------", "旋转角度是:"+angle+"------"+"-----"+mr);

        }
        
        }
}