Method for entropy-based determination of object edge curves
View Patent ↗In a method for determining object edge curves in a recorded image of a multispectral camera, the image recorded is converted into a false color image, hue value from the HSV color space is assigned to each pixel in the false color image such that the hue value corresponds to a hue angle on a predetermined color circle, and the pixels are classified as object pixels and background pixels, such that those pixels with hue values that are within a predetermined value range are defined as the object pixels. An entropy profile is then determined by way of a displaceable evaluation window, such that the entropy of mixing S is calculated for each pixel from the object pixels and background pixels according to the equation: S = - k ( n A ln n A n A + n B + n B ln n B n A + n B ) where n A denotes the number of object pixels within the evaluation window, n B denotes the number of background pixels within the evaluation window and k is a proportionality factor.
1. A method for determining object edge curves in a recorded image of a multispectral camera comprising:
converting the image recorded into a false color image,
assigning a hue value from a HSV color space to each pixel in the false color image, such that the hue value corresponds to a hue angle on a predetermined color circle,
classifying the pixels as object pixels and background pixels, such that pixels with hue values that are within a predetermined value range are defined as the object pixels,
determining an entropy profile, by way of a displaceable evaluation window, such that the entropy of mixing S is calculated for each pixel in the recorded image from the object pixels and background pixels according to the equation
S
=
-
k
(
n
A
ln
n
A
n
A
+
n
B
+
n
B
ln
n
B
n
A
+
n
B
)
where n A denotes the number of object pixels within the evaluation window, n B denotes the number of background pixels within the evaluation window and k is a proportionality factor, considering both differentiation and at least one extreme value of the entropy profile.
2. The method according to claim 1 , wherein, for determining the entropy profile, the entropy of mixing is calculated in an evaluation window of a predefinable length and width, such that the evaluation window is displaceable via the pixel classification created and the calculated entropy of mixing S assigned to the respective main pixel of the evaluation window, and further comprising shifting the evaluation window by at least one pixel in a direction of length, width, or both length and width, and repeatedly determining the entropy profile until an entropy of mixing has been assigned to each pixel.