Line structured light center extraction method for complicated surfaces

Aline structured light center extraction method for complicated surfaces, comprising the following steps:

• Step 1:
• processing a line structured light image by an extremum method and a connected domain filter method to determine an accurate reliable center point of a laser stripe, and using the accurate reliable center point of the laser stripe as a seed point of a center extraction algorithm, wherein in Step 1, a maximum pixel of the light stripe is obtained after the line structured light image is processed by the extremum method, a connected field area is calculated, an interference region with a small area and a reflective region with a width not meeting stripe features are filtered, a connected domain meeting stripe region features is used as a light stripe region, and the seed point of the algorithm is selected;
• by performing this step, a small interference region and a large reflective region are removed, and some pseudo stripe regions meeting corresponding features are taken as substitutive seed points;
• after the center line is extracted, multiple parallel center lines from different seed points are determined and estimated according to the length of the center line and connection with other determined center lines, and finally, an optimal center line is determined to ensure that a correct number of false seed points are extracted according to the center line in the following cases. Step 2:
• calculating an intensity representation value and a direction deviation representation value at the position of the seed point or a node according to a grayscale of the image in a half-cycle 180° direction, establishing a score function to determine an optimal stripe direction, and determining an optimal stripe fitting length to determine the position of a next node, wherein in Step 2, to express an intensity difference between the light stripe and a background region, an intensity representation value is established according to features of a high-brightness line laser stripe region, and an intensity extreme point is selected to express a high-brightness feature of the light stripe;
• for an excessively dark laser stripe caused by a dark surface, a direction continuity feature value θdev is established to represent a change of the stripe direction in two successive times of growing, and the small the value of the change of the stripe direction, the higher the continuity of the laser stripe, and the greater the possibility of the stripe direction;
• and finally, the score function is established to calculate extreme points of all intensity feature values, and a stripe direction corresponding to a maximum value of the score function is selected as a growth direction, as shown by the following formula:
• S
• =
• v
• θ
• θ
• dcv
• =
• v
• θ
• ❘
• "\[LeftBracketingBar]"
• θ
• new
• -
• θ
• old
• ❘
• "\[RightBracketingBar]"
• +
• δ
• .
• Step 3:
• extracting all nodes by growing, stopping an iterative operation when the grayscale of the image decreases drastically so as to obtain a center line of a line structured light stripe, and finally, extracting an accurate center point of the light stripe from a local region of the center line by a grayscale centroid method.