[英]Python cv2 90:90 aspect ratio rectangle to crop images
我正在编写一个程序来裁剪图像,我的问题是我希望该矩形具有特定的纵横比(90:90),是否可以制作矩形而不是鼠标,用鼠标滚轮更改其大小并用鼠标确认点击?
import cv2
import numpy as np
cropping = False
x_start, y_start, x_end, y_end = 0, 0, 0, 0
image = cv2.imread('example.jpg')
oriImage = image.copy()
def mouse_crop(event, x, y, flags, param):
# grab references to the global variables
global x_start, y_start, x_end, y_end, cropping
# if the left mouse button was DOWN, start RECORDING
# (x, y) coordinates and indicate that cropping is being
if event == cv2.EVENT_LBUTTONDOWN:
x_start, y_start, x_end, y_end = x, y, x, y
cropping = True
# Mouse is Moving
elif event == cv2.EVENT_MOUSEMOVE:
if cropping == True:
x_end, y_end = x, y
# if the left mouse button was released
elif event == cv2.EVENT_LBUTTONUP:
# record the ending (x, y) coordinates
x_end, y_end = x, y
cropping = False # cropping is finished
refPoint = [(x_start, y_start), (x_end, y_end)]
if len(refPoint) == 2: #when two points were found
roi = oriImage[refPoint[0][1]:refPoint[1][1], refPoint[0][0]:refPoint[1][0]]
cv2.imshow("Cropped", roi)
cv2.namedWindow("image")
cv2.setMouseCallback("image", mouse_crop)
while True:
i = image.copy()
if not cropping:
cv2.imshow("image", image)
elif cropping:
cv2.rectangle(i, (x_start, y_start), (x_end, y_end), (255, 0, 0), 2)
cv2.imshow("image", i)
cv2.waitKey(1)
# close all open windows
cv2.destroyAllWindows()
这是您可以用来执行此操作的基本结构。 第一次单击时创建一个初始矩形,通过向上或向下滚动调整矩形的大小,然后再次单击完成裁剪。 您需要添加一些检查以限制矩形超出图像边界和“小于零”时的矩形。
# if the left mouse button was released
if event == cv2.EVENT_LBUTTONUP:
# create rectangle
if not cropping:
x_start, y_start = x-20, y-20
x_end, y_end = x+20, y+20
cropping = True # cropping is finished
# finish cropping
else:
refPoint = [(x_start, y_start), (x_end, y_end)]
if len(refPoint) == 2: #when two points were found
roi = oriImage[refPoint[0][1]:refPoint[1][1], refPoint[0][0]:refPoint[1][0]]
cv2.imshow("Cropped", roi)
elif event == cv2.EVENT_MOUSEWHEEL:
print(flags)
# scroll up
if flags > 0:
x_start, y_start = x_start-2, y_start-2
x_end, y_end = x_end+2, y_end+2
# scroll down
else:
x_start, y_start = x_start+2, y_start+2
x_end, y_end = x_end-2, y_end-2
谢谢 :) 但我还有一个问题,我的代码现在看起来像这样:
import cv2
import numpy as np
cropping = False
x_start, y_start, x_end, y_end = 0, 0, 0, 0
image = cv2.imread('example.jpg')
oriImage = image.copy()
def mouse_crop(event, x, y, flags, param):
# grab references to the global variables
global x_start, y_start, x_end, y_end, cropping
# if the left mouse button was DOWN, start RECORDING
# (x, y) coordinates and indicate that cropping is being
if event == cv2.EVENT_MOUSEMOVE:
x_start, y_start, x_end, y_end = x, y, x+96, y+96
cropping = True
# Mouse is Moving
# elif event == cv2.EVENT_MOUSEMOVE:
# if cropping == True:
# x_end, y_end = x, y
# if the left mouse button was released
elif event == cv2.EVENT_LBUTTONUP:
# record the ending (x, y) coordinates
# x_end, y_end = x, y
cropping = False # cropping is finished
refPoint = [(x_start, y_start), (x_end, y_end)]
if len(refPoint) == 2: #when two points were found
roi = oriImage[refPoint[0][1]:refPoint[1][1], refPoint[0][0]:refPoint[1][0]]
cv2.imshow("Cropped", roi)
elif event == cv2.EVENT_MOUSEWHEEL:
print(flags)
# scroll up
if flags > 0:
x_start, y_start = x_start-15, y_start-15
x_end, y_end = x_end+15, y_end+15
# scroll down
else:
x_start, y_start = x_start+15, y_start+15
x_end, y_end = x_end-15, y_end-15
cv2.namedWindow("image")
cv2.setMouseCallback("image", mouse_crop)
while True:
i = image.copy()
if not cropping:
cv2.imshow("image", image)
elif cropping:
cv2.rectangle(i, (x_start, y_start), (x_end, y_end), (255, 0, 0), 2)
cv2.imshow("image", i)
cv2.waitKey(1)
# close all open windows
cv2.destroyAllWindows()
我的问题是:矩形跟随我的鼠标,我可以用鼠标滚轮让它越来越小,但是如果我把它变大并且鼠标移动,它又变小了
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