Python - QImage轉OpenCV處理的資料結構及相反轉換
阿新 • • 發佈：2018-12-09
軟體環境: Python3.6 / Python2.7 IDE: PYZO 傳送門: http://www.pyzo.org/
需要安裝的Python庫: numpy cv2 PyQt5 ，安裝方法如下
pip install numpy |
| pip install opencv-python |
| pip install PyQt5 |
個人推薦直接安裝Anaconda 3, Anaconda3已內建numpy與PyQt5，只需執行 pip install opencv-pyhton即可
鑑於需要閱讀本文的人應該都知道QImage和cv2,直接上程式碼，覺得有用的話，不妨點贊，讓我樂呵樂呵
cv_image = cv2.imread("圖片路徑") #此語句會返回一個opencv的圖片物件cv_image, 將image轉換為QImage的方法如下
def CV2QImage(cv_image): width = cv_image.shape[1] #獲取圖片寬度 height = cv_image.shape[0] #獲取圖片高度 pixmap = QPixmap(width, height) #根據已知的高度和寬度新建一個空的QPixmap, qimg = pixmap.toImage() #將pximap轉換為QImage型別的qimg #迴圈讀取cv_image的每個畫素的r,g,b值，構成qRgb物件，再設定為qimg內指定位置的畫素 for row in range(0, height): for col in range(0,width): r = cv_image[row,col,0] g = cv_image[row,col,1] b = cv_image[row,col,2] pix = qRgb(r, g, b) qimg.setPixel(col, row, pix) return qimg #轉換完成，返回
將QImage物件轉換為cv2可以直接處理的圖象，方法如下
def QImage2CV(qimg): tmp = qimg #使用numpy建立空的圖象 cv_image = numpy.zeros((tmp.height(), tmp.width(), 3), dtype=numpy.uint8) for row in range(0, tmp.height()): for col in range(0,tmp.width()): r = qRed(tmp.pixel(col, row)) g = qGreen(tmp.pixel(col, row)) b = qBlue(tmp.pixel(col, row)) cv_image[row,col,0] = r cv_image[row,col,1] = g cv_image[row,col,2] = b return cv_image
下面是測試上述兩個函式的完整測試例程
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import numpy as np
import cv2
def QImage2CV(qimg):
tmp = qimg
#使用numpy建立空的圖象
cv_image = np.zeros((tmp.height(), tmp.width(), 3), dtype=np.uint8)
for row in range(0, tmp.height()):
for col in range(0,tmp.width()):
r = qRed(tmp.pixel(col, row))
g = qGreen(tmp.pixel(col, row))
b = qBlue(tmp.pixel(col, row))
cv_image[row,col,0] = r
cv_image[row,col,1] = g
cv_image[row,col,2] = b
return cv_image
def CV2QImage(cv_image):
width = cv_image.shape[1] #獲取圖片寬度
height = cv_image.shape[0] #獲取圖片高度
pixmap = QPixmap(width, height) #根據已知的高度和寬度新建一個空的QPixmap,
qimg = pixmap.toImage() #將pximap轉換為QImage型別的qimg
#迴圈讀取cv_image的每個畫素的r,g,b值，構成qRgb物件，再設定為qimg內指定位置的畫素
for row in range(0, height):
for col in range(0,width):
r = cv_image[row,col,0]
g = cv_image[row,col,1]
b = cv_image[row,col,2]
pix = qRgb(r, g, b)
qimg.setPixel(col, row, pix)
return qimg #轉換完成，返回
path = "E:\\Temp\\" #存放測試圖片的路徑，請自行定義
qpixmap = QPixmap(500, 300)
qpixmap.fill(Qt.green)
painter = QPainter()
painter.begin(qpixmap)
painter.setPen(Qt.black)
painter.setBrush(Qt.white)
painter.drawEllipse(QRect(50, 100, 50, 100))
painter.drawLine(0,0,200,100)
painter.end()
qimg = qpixmap.toImage()
qimg.save(path + "qimg-origin.bmp")
image = QImage2CV(qimg)
start_point = (0, 0)
end_point = (250, 300)
line_width = 4
line_type = 8
color = (255,255,0)
cv2.line(image, start_point, end_point, color, line_width, line_type)
qimg_2 = CV2QImage(image)
qimg_2.save(path + "qimg-from-cv_img.bmp")
cv2.imshow("line", image)
cv2.waitKey()
cv2.destroyAllWindows()