Python 绘制筛选关键点

我正在使用SIFT关键点提取器/描述符在图像上提取和绘制关键点，如下代码所示：

import cv2 as cv 
img = cv.imread("my_img.jpg")
sift = cv.SIFT_create()
(keypoints, descriptors) = sift.detectAndCompute(img,None)
img_kp=cv.drawKeypoints(img,kp,cv.DRAW_MATCHES_FLAGS_DEFAULT,color=(120,157,187))
cv.imwrite("img.jpg", img_kp)

上面的代码将关键点绘制为橙色圆圈，如何将每个关键点的表示形式更改为橙色“+”符号

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非常感谢您的帮助

一个简单的解决方案可能是：迭代所有关键点并使用绘制一个“+”符号

下面是一个代码示例：

import numpy as np
import cv2


def draw_cross_keypoints(img, keypoints, color):
    """ Draw keypoints as crosses, and return the new image with the crosses. """
    img_kp = img.copy()  # Create a copy of img

    # Iterate over all keypoints and draw a cross on evey point.
    for kp in keypoints:
        x, y = kp.pt  # Each keypoint as an x, y tuple  https://stackoverflow.com/questions/35884409/how-to-extract-x-y-coordinates-from-opencv-cv2-keypoint-object

        x = int(round(x))  # Round an cast to int
        y = int(round(y))

        # Draw a cross with (x, y) center
        cv2.drawMarker(img_kp, (x, y), color, markerType=cv2.MARKER_CROSS, markerSize=5, thickness=1, line_type=cv2.LINE_8)

    return img_kp  # Return the image with the drawn crosses.


img = cv2.imread("my_img.jpg")
sift = cv2.SIFT_create()
(keypoints, descriptors) = sift.detectAndCompute(img, None)
#img_kp = cv2.drawKeypoints(img, keypoints, cv2.DRAW_MATCHES_FLAGS_DEFAULT, color=(120,157,187))
img_kp = draw_cross_keypoints(img, keypoints, color=(120,157,187))  # Draw keypoints as "+" signs
cv2.imwrite("img.jpg", img_kp)

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样本结果：

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十字和圆圈-用于测试：

如您所见，“+”符号位于圆圈的中心