一、概述

        该算法使用区域邻域恢复图像中的选定区域。该功能可用于去除扫描照片上的灰尘和划痕，或去除静止图像或视频中不需要的物体。

二、inpaint函数

1、函数原型

void 	cv::inpaint (InputArray src, InputArray inpaintMask, OutputArray dst, double inpaintRadius, int flags)

2、参数详解

src	输入 8 位、16 位无符号或 32 位浮点 1 通道或 8 位 3 通道图像。
inpaintMask	修复蒙版，8 位 1 通道图像。 非零像素表示需要修复的区域。
dst	输出与 src 大小和类型相同的图像
inpaintRadius	算法考虑的每个修复点的圆形邻域的半径。
flags	可以是 cv::INPAINT_NS 或 cv::INPAINT_TELEA 的修复方法

三、OpenCV源码

1、源码路径

opencv\modules\photo\src\inpaint.cpp

2、源码代码

static void
icvInpaint( const CvArr* _input_img, const CvArr* _inpaint_mask, CvArr* _output_img,
           double inpaintRange, int flags )
{
    cv::Ptr<CvMat> mask, band, f, t, out;
    cv::Ptr<CvPriorityQueueFloat> Heap, Out;
    cv::Ptr<IplConvKernel> el_cross, el_range;

    CvMat input_hdr, mask_hdr, output_hdr;
    CvMat* input_img, *inpaint_mask, *output_img;
    int range=cvRound(inpaintRange);
    int erows, ecols;

    input_img = cvGetMat( _input_img, &input_hdr );
    inpaint_mask = cvGetMat( _inpaint_mask, &mask_hdr );
    output_img = cvGetMat( _output_img, &output_hdr );

    if( !CV_ARE_SIZES_EQ(input_img,output_img) || !CV_ARE_SIZES_EQ(input_img,inpaint_mask))
        CV_Error( CV_StsUnmatchedSizes, "All the input and output images must have the same size" );

    if( (CV_MAT_TYPE(input_img->type) != CV_8U &&
         CV_MAT_TYPE(input_img->type) != CV_16U &&
         CV_MAT_TYPE(input_img->type) != CV_32F &&
        CV_MAT_TYPE(input_img->type) != CV_8UC3) ||
        !CV_ARE_TYPES_EQ(input_img,output_img) )
        CV_Error( CV_StsUnsupportedFormat,
        "8-bit, 16-bit unsigned or 32-bit float 1-channel and 8-bit 3-channel input/output images are supported" );

    if( CV_MAT_TYPE(inpaint_mask->type) != CV_8UC1 )
        CV_Error( CV_StsUnsupportedFormat, "The mask must be 8-bit 1-channel image" );

    range = MAX(range,1);
    range = MIN(range,100);

    ecols = input_img->cols + 2;
    erows = input_img->rows + 2;

    f.reset(cvCreateMat(erows, ecols, CV_8UC1));
    t.reset(cvCreateMat(erows, ecols, CV_32FC1));
    band.reset(cvCreateMat(erows, ecols, CV_8UC1));
    mask.reset(cvCreateMat(erows, ecols, CV_8UC1));
    el_cross.reset(cvCreateStructuringElementEx(3,3,1,1,CV_SHAPE_CROSS,NULL));

    cvCopy( input_img, output_img );
    cvSet(mask,cvScalar(KNOWN,0,0,0));
    COPY_MASK_BORDER1_C1(inpaint_mask,mask,uchar);
    SET_BORDER1_C1(mask,uchar,0);
    cvSet(f,cvScalar(KNOWN,0,0,0));
    cvSet(t,cvScalar(1.0e6f,0,0,0));
    cvDilate(mask,band,el_cross,1);   // image with narrow band
    Heap=cv::makePtr<CvPriorityQueueFloat>();
    if (!Heap->Init(band))
        return;
    cvSub(band,mask,band,NULL);
    SET_BORDER1_C1(band,uchar,0);
    if (!Heap->Add(band))
        return;
    cvSet(f,cvScalar(BAND,0,0,0),band);
    cvSet(f,cvScalar(INSIDE,0,0,0),mask);
    cvSet(t,cvScalar(0,0,0,0),band);

    if( flags == cv::INPAINT_TELEA )
    {
        out.reset(cvCreateMat(erows, ecols, CV_8UC1));
        el_range.reset(cvCreateStructuringElementEx(2*range+1,2*range+1,
            range,range,CV_SHAPE_RECT,NULL));
        cvDilate(mask,out,el_range,1);
        cvSub(out,mask,out,NULL);
        Out=cv::makePtr<CvPriorityQueueFloat>();
        if (!Out->Init(out))
            return;
        if (!Out->Add(band))
            return;
        cvSub(out,band,out,NULL);
        SET_BORDER1_C1(out,uchar,0);
        icvCalcFMM(out,t,Out,true);
        switch(CV_MAT_DEPTH(output_img->type))
        {
            case CV_8U:
                icvTeleaInpaintFMM<uchar>(mask,t,output_img,range,Heap);
                break;
            case CV_16U:
                icvTeleaInpaintFMM<ushort>(mask,t,output_img,range,Heap);
                break;
            case CV_32F:
                icvTeleaInpaintFMM<float>(mask,t,output_img,range,Heap);
                break;
            default:
                CV_Error( cv::Error::StsBadArg, "Unsupportedformat of the input image" );
        }
    }
    else if (flags == cv::INPAINT_NS) {
        switch(CV_MAT_DEPTH(output_img->type))
        {
            case CV_8U:
                icvNSInpaintFMM<uchar>(mask,t,output_img,range,Heap);
                break;
            case CV_16U:
                icvNSInpaintFMM<ushort>(mask,t,output_img,range,Heap);
                break;
            case CV_32F:
                icvNSInpaintFMM<float>(mask,t,output_img,range,Heap);
                break;
            default:
                CV_Error( cv::Error::StsBadArg, "Unsupported format of the input image" );
        }
    } else {
        CV_Error( cv::Error::StsBadArg, "The flags argument must be one of CV_INPAINT_TELEA or CV_INPAINT_NS" );
    }
}

void cv::inpaint( InputArray _src, InputArray _mask, OutputArray _dst,
                  double inpaintRange, int flags )
{
    CV_INSTRUMENT_REGION();

    Mat src = _src.getMat(), mask = _mask.getMat();
    _dst.create( src.size(), src.type() );
    Mat dst = _dst.getMat();
    CvMat c_src = cvMat(src), c_mask = cvMat(mask), c_dst = cvMat(dst);
    icvInpaint( &c_src, &c_mask, &c_dst, inpaintRange, flags );
}

四、效果图像示例

待修复的图像

基于 Navier-Stokes 的方法

基于Alexandru Telea 的方法