Finds lines in a binary image using the standard Hough transform

lines = cv.HoughLines(image)
lines = cv.HoughLines(..., 'OptionName', optionValue, ...)

Input

• image 8-bit, single-channel binary source image.

Output

• lines Output vector of lines. A cell-array of 2-element vectors {[rho,theta], ...}. rho is the distance from the coordinate origin (0,0) (top-left corner of the image). theta is the line rotation angle in radians (0 ~ vertical line, pi/2 ~ horizontal line).

Options

• Rho Distance resolution of the accumulator in pixels. default 1.
• Theta Angle resolution of the accumulator in radians. default pi/180.
• Threshold Accumulator threshold parameter. Only those lines are returned that get enough votes (>Threshold). default 80.
• SRN For the multi-scale Hough transform, it is a divisor for the distance resolution Rho. The coarse accumulator distance resolution is Rho and the accurate accumulator resolution is Rho/SRN. If both SRN=0 and STN=0, the classical Hough transform is used. Otherwise, both these parameters should be positive. default 0.
• STN For the multi-scale Hough transform, it is a divisor for the distance resolution Theta. default 0.
• MinTheta For standard and multi-scale Hough transform, minimum angle to check for lines. Must fall between 0 and MaxTheta. default 0
• MaxTheta For standard and multi-scale Hough transform, maximum angle to check for lines. Must fall between MinTheta and pi. default pi

The function implements the standard or standard multi-scale Hough transform algorithm for line detection. See this for a good explanation of Hough transform.