TIEVisionImage.houghLines
Declaration
function houghLines(rho: double; theta: double; threshold: int32_t; srn: double = 0; stn: double = 0): TIEVisionVectorFloatPair; safecall;Description
Find lines in a binary image using the standard Hough transform.Returns a vector (list) of lines. Each line is represented by a two-element vector, where the first value is the distance from the coordinate origin (p) and the second value is the angle to the center of that perpindicular line (theta).
Note:
◼Pixel format of input image must be ie8g
◼You can draw the lines to a canvas using DrawLines
◼For a probabilistic Hough transform, use houghLinesP
| Parameter | Description |
|---|---|
| rho | Distance resolution of the accumulator in pixels |
| theta | Angle resolution of the accumulator in radians |
| threshold | Accumulator threshold parameter. Only those lines are returned that get enough votes |
| srn | For the multi-scale Hough transform, it is a divisor for the distance resolution rho |
| stn | For the multi-scale Hough transform, it is a divisor for the distance resolution theta |
Demo
 | Demos\IEVision\LinesDetect\LinesDetect.dpr |
Example
ImageEnView1.IO.LoadFromFile('input.jpg');ImageEnView1.IEBitmap.PixelFormat := ie8g;
ImageEnView1.IEBitmap.GetIEVisionImage().blur(IEVisionSize(3, 3), IEVisionPoint(-1, -1));
ImageEnView1.IEBitmap.GetIEVisionImage().canny(50, 200, 3);
lines := ImageEnView1.IEBitmap.GetIEVisionImage().houghLines(1, PI / 180, 200);