如何使用OpenCV Python找到一种颜色的HSV值？

百变鹏仔 3小时前 #Python

文章标签如何使用

要找到一个颜色的HSV值，我们可以使用从BGR到HSV的颜色空间转换。首先，我们将颜色值以BGR格式定义为numpy.ndarray，然后将其转换为HSV空间。

We can also find the lower and upper limits of HSV value as [H-10, 100, 100] and [H+10, 255, 255] respectively. These lower and upper limits can be used to track an object of particular color.

要找到一个颜色的HSV值，请按照以下步骤进行：

步骤

Import the required libraries. In all the following Python examples, the required Python libraries are OpenCV and NumPy. Make sure you have already installed them.

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import cv2import numpy as np

为颜色定义一个numpy.ndarray，dtype=np.uint8。

green = np.uint8([[[0, 255, 0]]])

Convert the above defined color to HSV.

hsvGreen = cv2.cvtColor(green, cv2.COLOR_BGR2HSV)

Print the color values.

print("HSV of Green:", hsvGreen)

Let's look at some program examples to understand it clearly.

Example 1

In this example, we find the HSV value for green color. The BGR value of green is [0,255,0].

# import required librariesimport numpy as npimport cv2# define a numpy.ndarray for the color# here insert the bgr values which you want to convert to hsvgreen = np.uint8([[[0, 255, 0]]])# convert the color to HSVhsvGreen = cv2.cvtColor(green, cv2.COLOR_BGR2HSV)# display the color valuesprint("BGR of Green:", green)print("HSV of Green:", hsvGreen)# Compute the lower and upper limitslowerLimit = hsvGreen[0][0][0] - 10, 100, 100upperLimit = hsvGreen[0][0][0] + 10, 255, 255# display the lower and upper limitsprint("Lower Limit:",lowerLimit)print("Upper Limit", upperLimit)

输出

When you run the above Python program, it will produce the following output −

BGR of Green: [[[ 0 255 0]]] HSV of Green: [[[ 60 255 255]]] Lower Limit: (50, 100, 100) Upper Limit (70, 255, 255)

Example 2

的中文翻译为：

示例 2

In this example, we find the HSV value for a color whose BGR value is [106,76,89].

# import required librariesimport numpy as npimport cv2green = np.uint8([[[0, 255, 0]]])# convert the color to HSVhsvGreen = cv2.cvtColor(green, cv2.COLOR_BGR2HSV)# here insert the bgr values which you want to convert to hsvbgr = np.uint8([[[106,76,89]]])hsv = cv2.cvtColor(green, cv2.COLOR_BGR2HSV)print("BGR Value:", bgr)print("HSV Value:", hsv)# compute the lower and upper limitslowerLimit = hsvGreen[0][0][0] - 10, 100, 100upperLimit = hsvGreen[0][0][0] + 10, 255, 255# display the lower and upper limitsprint("Lower Limit:",lowerLimit)print("Upper Limit", upperLimit)

输出

When you run the above python program, it will produce the following output −

BGR Value: [[[76 76 89]]] HSV Value: [[[ 60 255 255]]] Lower Limit: (50, 100, 100) Upper Limit (70, 255, 255)

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如何使用OpenCV Python找到一种颜色的HSV值？

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示例 2

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