去除图片黑色边框及折角部分的黑色边框（彩色图像和灰度图像均可）

/************************************************************************/
/* 消除图片四周的黑色边框                                               */
/************************************************************************/
void RemoveBlackBorder(Mat &iplImg, Mat &dstImg)
{
int width = iplImg.size().width;
int height = iplImg.size().height;
int a = 0, b = 0, c = 0, d = 0;
int i = 0, j = 0;

if (iplImg.channels() == 1)	//灰度图片
{
//消除黑色边框：上
for (j = 0; j<height; j++)
{
bool flag = false;
for (i = 0; i<width; i++)
{
if (iplImg.at<uchar>(j, i)<30)
{
;
}
else
{
flag = true;
a = j;
break;
}
}
if (flag) break;
}
//消除黑色边框：下
for (j = height - 1; j >= a; j--)
{
bool flag = false;
for (i = 0; i<width; i++)
{
if (iplImg.at<uchar>(j, i)<30)
{
;
}
else
{
flag = true;
b = j;
break;
}
}
if (flag) break;
}
//消除黑色边框：左
for (i = 0; i<width; i++)
{
bool flag = false;
for (j = 0; j<height; j++)
{
if (iplImg.at<uchar>(j, i)<30)
{
;
}
else
{
flag = true;
c = i;
break;
}
}
if (flag) break;
}
//消除黑色边框：右
for (i = width - 1; i >= c; i--)
{
bool flag = false;
for (j = 0; j<height; j++)
{
if (iplImg.at<uchar>(j, i)<30)
{
;
}
else
{
flag = true;
d = i;
break;
}
}
if (flag) break;
}
}
else if (iplImg.channels() == 3)	//彩色图片
{
//消除黑色边框：上
for (j = 0; j < height; j++)
{
bool flag = false;
for (i = 0; i < width; i++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)iplImg, j, i).val[0];
tmpg = cvGet2D(&(IplImage)iplImg, j, i).val[1];
tmpr = cvGet2D(&(IplImage)iplImg, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
;
}
else
{
flag = true;
a = j;
break;
}
}
if (flag) break;
}
//printf("上 a: %d\n", a);

//消除黑色边框：下
for (j = height - 1; j >= a; j--)
{
bool flag = false;
for (i = 0; i < width; i++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)iplImg, j, i).val[0];
tmpg = cvGet2D(&(IplImage)iplImg, j, i).val[1];
tmpr = cvGet2D(&(IplImage)iplImg, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
;
}
else
{
flag = true;
b = j;
break;
}
}
if (flag) break;
}
//printf("下 b: %d\n", b);

//消除黑色边框：左
for (i = 0; i < width; i++)
{
bool flag = false;
for (j = 0; j < height; j++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)iplImg, j, i).val[0];
tmpg = cvGet2D(&(IplImage)iplImg, j, i).val[1];
tmpr = cvGet2D(&(IplImage)iplImg, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
;
}
else
{
flag = true;
c = i;
break;
}
}
if (flag) break;
}
//printf("左 c: %d\n", c);

//消除黑色边框：右
for (i = width - 1; i >= c; i--)
{
bool flag = false;
for (j = 0; j < height; j++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)iplImg, j, i).val[0];
tmpg = cvGet2D(&(IplImage)iplImg, j, i).val[1];
tmpr = cvGet2D(&(IplImage)iplImg, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
;
}
else
{
flag = true;
d = i;
break;
}
}
if (flag) break;
}
//printf("右 d: %d\n", d);
}

//复制图像
int w = d - c + 1, h = b - a + 1;
dstImg = Mat(iplImg, Rect(c, a, w, h));

return;
}

/************************************************************************/
/* 消除图片四周的黑色边角区域                                           */
/************************************************************************/
Mat RemoveBlackCorner(Mat img)
{
int i, j;
int h = img.size().height;
int w = img.size().width;

if (img.channels() == 1)	//灰度图片
{
for (j = 0; j<h; j++)
{
for (i = 0; i<w; i++)
{
if (img.at<uchar>(j, i)<30)
{
img.at<uchar>(j, i) = 255;
}
else
{
break;
}
}
for (i = w - 1; i >= 0; i--)
{
if (img.at<uchar>(j, i)<30)
{
img.at<uchar>(j, i) = 255;
}
else
{
break;
}
}
}
for (i = 0; i<w; i++)
{
for (j = 0; j<h; j++)
{
if (img.at<uchar>(j, i)<30)
{
img.at<uchar>(j, i) = 255;
}
else
{
break;
}
}
for (j = h - 1; j >= 0; j--)
{
if (img.at<uchar>(j, i)<30)
{
img.at<uchar>(j, i) = 255;
}
else
{
break;
}
}
}
}
else if (img.channels() == 3)	//彩色图片
{
for (j = 0; j<h; j++)
{
for (i = 0; i<w; i++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)img, j, i).val[0];
tmpg = cvGet2D(&(IplImage)img, j, i).val[1];
tmpr = cvGet2D(&(IplImage)img, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
cvSet2D(&(IplImage)img, j, i, CvScalar(255, 255, 255, 0));
}
else
{
break;
}
}
for (i = w - 1; i >= 0; i--)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)img, j, i).val[0];
tmpg = cvGet2D(&(IplImage)img, j, i).val[1];
tmpr = cvGet2D(&(IplImage)img, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
cvSet2D(&(IplImage)img, j, i, CvScalar(255, 255, 255, 0));
}
else
{
break;
}
}
}
for (i = 0; i<w; i++)
{
for (j = 0; j<h; j++)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)img, j, i).val[0];
tmpg = cvGet2D(&(IplImage)img, j, i).val[1];
tmpr = cvGet2D(&(IplImage)img, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
cvSet2D(&(IplImage)img, j, i, CvScalar(255, 255, 255, 0));
}
else
{
break;
}
}
for (j = h - 1; j >= 0; j--)
{
int tmpb, tmpg, tmpr;
tmpb = cvGet2D(&(IplImage)img, j, i).val[0];
tmpg = cvGet2D(&(IplImage)img, j, i).val[1];
tmpr = cvGet2D(&(IplImage)img, j, i).val[2];
if (tmpb <= 30 && tmpg <= 30 && tmpr <= 30)
{
cvSet2D(&(IplImage)img, j, i, CvScalar(255, 255, 255, 0));
}
else
{
break;
}
}
}
}

return img;
}

int main()
{
Mat iplImg = imread("ori.jpg", CV_LOAD_IMAGE_ANYCOLOR | CV_LOAD_IMAGE_ANYDEPTH);
Mat img;
RemoveBlackBorder(iplImg, img);
imwrite("1.png", img);

img = RemoveBlackCorner(img);
imwrite("2.png", img);

cout << "OK" << endl;
getchar();
return 0;
}