C# OpenCvSharp、ZXing.net读取QR码

1.检测思路

2.代码

Mat src = new Mat("qrcode2.bmp");
#region 图像增强
//Opencvsharp实现图像增强
int[] min = new int[] { 40, 0 }; //参数需微调，根据检测结果
int[] max = new int[] { 220, 255 }; //参数需微调，根据检测结果
Scale_image_inrange(src, out Mat scaleimage, min, max); //灰度变换，图像增强
//Cv2.ImShow("scale", scaleimage);  
#endregion

QRCodeDetector qrdetector = new QRCodeDetector(); //实例一个qr码检测设备
qrdetector.Detect(src, out Point2f[] point2f); //检测是否存在qr码,通过输出的二维码位置信息进行图像裁剪
//
//图像裁剪，此处由于使用halcon进行roi裁剪，未展示opencvsharp的裁剪图像代码
//

QRCodeReader QRReader = new QRCodeReader(); //实例一个qr码读取设备
//Bitmap2BinaryBitmap(BitmapConverter.ToBitmap(src), out BinaryBitmap bbmp); //Bitmap转为BinaryBitmap，
                                                                                               //QRCodeReader.Decode()接收图像为ZXing.BinaryBitmap
IDictionary<DecodeHintType, object> hints = new Dictionary<DecodeHintType, object>(); //定义读码的参数
hints.Add(DecodeHintType.TRY_HARDER, true); 
hints.Add(DecodeHintType.POSSIBLE_FORMATS, BarcodeFormat.QR_CODE);
hints.Add(DecodeHintType.TRY_HARDER_WITHOUT_ROTATION, true);
int angle = 360;
int steplength = 5;
OpenCvSharp.Point centerp = new OpenCvSharp.Point(src.Cols / 2, src.Rows / 2); //获取图像中心
Bitmap rotbmp;
for (int i = 1; i < angle / 5; i++) //旋转图像
 {
//                                  旋转中心，旋转角度，缩放
Mat rot_mat = Cv2.GetRotationMatrix2D(centerp, steplength * i, 1); //获取仿射矩阵
Mat rotate_image = new Mat();
Cv2.WarpAffine(scaleimage, rotate_image, rot_mat, new OpenCvSharp.Size(src.Cols, src.Rows)); //应用仿射变换
rotbmp = BitmapConverter.ToBitmap(rotate_image);
// rotbmp.Save($"Image//Image{i}_{i*5}°.bmp");
Bitmap2BinaryBitmap(rotbmp, out BinaryBitmap bbmp1);//Bitmap转为BinaryBitmap，
                                                                            //QRCodeReader.Decode()接收图像为ZXing.BinaryBitmap
Result res = QRReader.decode(bbmp1, hints); //读码
if (res != null)
{
listBox1.Items.Add(res.Text + $"旋转{i}次读取成功");
pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
pictureBox1.Image = rotbmp;
sw.Stop();
MessageBox.Show(sw.ElapsedMilliseconds.ToString());
return;
}
}



/// <summary>
/// Bitmap ConvertTo BinaryBitmap
/// </summary> 
/// <param name="bitmap">位图</param>
/// <param name="binarybitmap">ZXing的二进制位图</param>
public void Bitmap2BinaryBitmap(Bitmap bitmap, out BinaryBitmap binarybitmap)
{
            BinaryBitmap bbmp;
            try
            {
                if (bitmap != null)
                {
                    LuminanceSource source = new BitmapLuminanceSource(bitmap);
                    var binarizer = new GlobalHistogramBinarizer(source);
                    bbmp = new BinaryBitmap(binarizer);
                    binarybitmap = bbmp;
                }
                else
                {
                    binarybitmap = null;
                }
            }
            catch
            {
                binarybitmap = null;
            }
}


/// <summary>
/// 阈值灰度变换
/// If the image shall be scaled to an interval different from [0,255],
/// this can be achieved by passing tuples with 2 values[From, To]
/// as Min and Max.
/// </summary>
/// <param name="src">InputImage</param>
/// <param name="scalemat">OutputImage</param>
/// <param name="min">min[From,To]</param>
/// <param name="max">max[From,To]</param>
public void Scale_image_inrange(Mat src,out Mat scalemat,int [] min,int [] max)
{
            scalemat = new Mat();
            int Min = 0;
            int Max = 0;
            int LowerLimit;
            int UpperLimit;
            double Mult;
            double Add;
            if (min.Length == 2)
            {
                LowerLimit = min[1];
                Min = min[0];
            }
            else
            {
                LowerLimit = 0;
            }
            if (max.Length == 2)
            {
                UpperLimit = max[1];
                Max = max[0];
            }
            else
            {
                UpperLimit = 255;
            }

            Mult = (double)(UpperLimit - LowerLimit) / (Max - Min);
            Add = (double)(-Mult * Min + LowerLimit);
            Cv2.ConvertScaleAbs(src,scalemat,Mult,Add);     
}