mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-30 16:31:08 +00:00
7a14285cb6
* Added Lstm example for stock predection
* Changes after review
* changes after build failed
* Add Kiera’s to requirements.txt
* requirements.txt: Add keras and tensorflow
* psf/black
* haris corner detection
* fixup! Format Python code with psf/black push
* changes after review
* changes after review
* fixup! Format Python code with psf/black push
Co-authored-by: Christian Clauss <cclauss@me.com>
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
76 lines
2.1 KiB
Python
76 lines
2.1 KiB
Python
import numpy as np
|
|
import cv2
|
|
|
|
"""
|
|
Harris Corner Detector
|
|
https://en.wikipedia.org/wiki/Harris_Corner_Detector
|
|
"""
|
|
|
|
|
|
class Harris_Corner:
|
|
def __init__(self, k: float, window_size: int):
|
|
|
|
"""
|
|
k : is an empirically determined constant in [0.04,0.06]
|
|
window_size : neighbourhoods considered
|
|
"""
|
|
|
|
if k in (0.04, 0.06):
|
|
self.k = k
|
|
self.window_size = window_size
|
|
else:
|
|
raise ValueError("invalid k value")
|
|
|
|
def __str__(self):
|
|
|
|
return f"Harris Corner detection with k : {self.k}"
|
|
|
|
def detect(self, img_path: str):
|
|
|
|
"""
|
|
Returns the image with corners identified
|
|
img_path : path of the image
|
|
output : list of the corner positions, image
|
|
"""
|
|
|
|
img = cv2.imread(img_path, 0)
|
|
h, w = img.shape
|
|
corner_list = []
|
|
color_img = img.copy()
|
|
color_img = cv2.cvtColor(color_img, cv2.COLOR_GRAY2RGB)
|
|
dy, dx = np.gradient(img)
|
|
ixx = dx ** 2
|
|
iyy = dy ** 2
|
|
ixy = dx * dy
|
|
k = 0.04
|
|
offset = self.window_size // 2
|
|
for y in range(offset, h - offset):
|
|
for x in range(offset, w - offset):
|
|
wxx = ixx[
|
|
y - offset : y + offset + 1, x - offset : x + offset + 1
|
|
].sum()
|
|
wyy = iyy[
|
|
y - offset : y + offset + 1, x - offset : x + offset + 1
|
|
].sum()
|
|
wxy = ixy[
|
|
y - offset : y + offset + 1, x - offset : x + offset + 1
|
|
].sum()
|
|
|
|
det = (wxx * wyy) - (wxy ** 2)
|
|
trace = wxx + wyy
|
|
r = det - k * (trace ** 2)
|
|
# Can change the value
|
|
if r > 0.5:
|
|
corner_list.append([x, y, r])
|
|
color_img.itemset((y, x, 0), 0)
|
|
color_img.itemset((y, x, 1), 0)
|
|
color_img.itemset((y, x, 2), 255)
|
|
return color_img, corner_list
|
|
|
|
|
|
if __name__ == "__main__":
|
|
|
|
edge_detect = Harris_Corner(0.04, 3)
|
|
color_img, _ = edge_detect.detect("path_to_image")
|
|
cv2.imwrite("detect.png", color_img)
|