Question

我知道 Matlab, matplotlib style colormap in OpenCV 。该文档解释了它对C ++的用法。我想知道是否存在使用cv2的python这样的选项。我google了很多，什么都没发现。我知道matplotlib的colormap选项，我可以使用，但如果cv2提供这样的选项，我可以消除将matplotlib colormaps转换为opencv图像的开销。它笨拙。我需要它用于我的项目。

Answer 1

对于OpenCV 2.4.11，applyColorMap适用于Python（即使2.4.11 docs仍然只列出C ++）：

import cv2
im = cv2.imread('test.jpg', cv2.IMREAD_GRAYSCALE)
imC = cv2.applyColorMap(im, cv2.COLORMAP_JET)

另见this Stack Overflow answer。

Answer 2

羞耻，看起来它还没有进入python api。但你可以看看modules / contrib / src / colormap.cpp中的实现，例如jetmap只是一个查找表，你可以偷它

Answer 3

可悲的是，OpenCV没有任何colorMap，但你可以写一个。没那么困难。

class ColorMap:
    startcolor = ()
    endcolor = ()
    startmap = 0
    endmap = 0
    colordistance = 0
    valuerange = 0
    ratios = []    

    def __init__(self, startcolor, endcolor, startmap, endmap):
        self.startcolor = np.array(startcolor)
        self.endcolor = np.array(endcolor)
        self.startmap = float(startmap)
        self.endmap = float(endmap)
        self.valuerange = float(endmap - startmap)
        self.ratios = (self.endcolor - self.startcolor) / self.valuerange

    def __getitem__(self, value):
        color = tuple(self.startcolor + (self.ratios * (value - self.startmap)))
        return (int(color[0]), int(color[1]), int(color[2]))

Answer 4

无法在 Python 中使用之前的 applyColorMap 示例。以为我分享。我为“胖”道歉。如果您的摄像机未被识别，或者有多个摄像机，请将“1”替换为“0”

import cv2
import numpy as np

frameWidth = 940
frameHeight = 680
cap = cv2.VideoCapture(0)
cap.set(3, frameWidth)  # 3=width, 4=height
cap.set(4, frameHeight)

while True:
    success, imgColor, = cap.read()
    img = cv2.resize(imgColor, (frameWidth, frameHeight))  # if want to resize frame
    
    # ORIG IMG
    cv2.moveWindow("img", 0, 0)  # relocate shift reposition move so frame is at top left corner of monitor
    cv2.imshow("img", img)
    
    # COLOR ENHANCED
    cv2.moveWindow("imgColor", frameWidth, 0)  # relocate shift reposition move to side by side
    # COLORMAP_AUTUMN = 0
    # COLORMAP_BONE = 1
    # COLORMAP_COOL = 8
    # COLORMAP_HOT = 11
    # COLORMAP_HSV = 9
    # COLORMAP_JET = 2
    # COLORMAP_OCEAN = 5
    # COLORMAP_PINK = 10
    # COLORMAP_RAINBOW = 4
    # COLORMAP_SPRING = 7
    # COLORMAP_SUMMER = 6
    # COLORMAP_WINTER = 3
    cv2.imshow("imgColor", cv2.applyColorMap(imgColor, 3))  # change the last variable in here

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

python中有OpenCV colormap吗？

4 个答案: