OpenCV
3.1.0-dev
Open Source Computer Vision
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Modules | |
Structured forests for fast edge detection | |
Filters | |
Superpixels | |
Image segmentation | |
Functions | |
void | cv::ximgproc::niBlackThreshold (InputArray _src, OutputArray _dst, double maxValue, int type, int blockSize, double delta) |
Applies Niblack thresholding to input image. More... | |
void | cv::ximgproc::thinning (InputArray src, OutputArray dst) |
Applies a binary blob thinning operation, to achieve a skeletization of the input image. More... | |
void cv::ximgproc::niBlackThreshold | ( | InputArray | _src, |
OutputArray | _dst, | ||
double | maxValue, | ||
int | type, | ||
int | blockSize, | ||
double | delta | ||
) |
Applies Niblack thresholding to input image.
The function transforms a grayscale image to a binary image according to the formulae:
\[dst(x,y) = \fork{\texttt{maxValue}}{if \(src(x,y) > T(x,y)\)}{0}{otherwise}\]
\[dst(x,y) = \fork{0}{if \(src(x,y) > T(x,y)\)}{\texttt{maxValue}}{otherwise}\]
where \(T(x,y)\) is a threshold calculated individually for each pixel.The threshold value \(T(x, y)\) is the mean minus \( delta \) times standard deviation of \(\texttt{blockSize} \times\texttt{blockSize}\) neighborhood of \((x, y)\).
The function can't process the image in-place.
_src | Source 8-bit single-channel image. |
_dst | Destination image of the same size and the same type as src. |
maxValue | Non-zero value assigned to the pixels for which the condition is satisfied, used with the THRESH_BINARY and THRESH_BINARY_INV thresholding types. |
type | Thresholding type, see cv::ThresholdTypes. |
blockSize | Size of a pixel neighborhood that is used to calculate a threshold value for the pixel: 3, 5, 7, and so on. |
delta | Constant multiplied with the standard deviation and subtracted from the mean. Normally, it is taken to be a real number between 0 and 1. |
void cv::ximgproc::thinning | ( | InputArray | src, |
OutputArray | dst | ||
) |
Applies a binary blob thinning operation, to achieve a skeletization of the input image.
The function transforms a binary blob image into a skeletized form using the technique of Zhang-Suen.
src | Source 8-bit single-channel image, containing binary blobs, with blobs having 255 pixel values. |
dst | Destination image of the same size and the same type as src. The function can work in-place. |