如何用一种纯色填充OpenCV图像？

Question

如何用一种纯色填充OpenCV图像？

Answer 1

使用OpenCV C API IplImage* img:

使用cvSet():cvSet(img, CV_RGB(redVal,greenVal,blueVal));

使用OpenCV C++ API cv::Mat img,然后使用:

cv::Mat::operator=(const Scalar& s) 如:

img = cv::Scalar(redVal,greenVal,blueVal);

或更普遍的面具支持,cv::Mat::setTo():

img.setTo(cv::Scalar(redVal,greenVal,blueVal));

Answer 2

以下是如何在Python中使用cv2:

# Create a blank 300x300 black image
image = np.zeros((300, 300, 3), np.uint8)
# Fill image with red color(set each pixel to red)
image[:] = (0, 0, 255)

这里有更完整的示例如何创建填充了某种RGB颜色的新空白图像

import cv2
import numpy as np

def create_blank(width, height, rgb_color=(0, 0, 0)):
    """Create new image(numpy array) filled with certain color in RGB"""
    # Create black blank image
    image = np.zeros((height, width, 3), np.uint8)

    # Since OpenCV uses BGR, convert the color first
    color = tuple(reversed(rgb_color))
    # Fill image with color
    image[:] = color

    return image

# Create new blank 300x300 red image
width, height = 300, 300

red = (255, 0, 0)
image = create_blank(width, height, rgb_color=red)
cv2.imwrite('red.jpg', image)

Answer 3

最简单的是使用OpenCV Mat类:

img=cv::Scalar(blue_value, green_value, red_value);

在哪里img定义为cv::Mat.

Answer 4

创建一个新的640x480图像,并用紫色(红色+蓝色)填充它:

cv::Mat mat(480, 640, CV_8UC3, cv::Scalar(255,0,255));

注意:

• 宽度前的高度
• 类型CV_8UC3表示8位无符号整数,3个通道
• 颜色格式是BGR

Answer 5

使用numpy.full. 这是一个创建灰色、蓝色、绿色和红色图像并显示在 2x2 网格中的 Python。

import cv2
import numpy as np

gray_img = np.full((100, 100, 3), 127, np.uint8)

blue_img = np.full((100, 100, 3), 0, np.uint8)
green_img = np.full((100, 100, 3), 0, np.uint8)
red_img = np.full((100, 100, 3), 0, np.uint8)

full_layer = np.full((100, 100), 255, np.uint8)

# OpenCV goes in blue, green, red order
blue_img[:, :, 0] = full_layer
green_img[:, :, 1] = full_layer
red_img[:, :, 2] = full_layer

cv2.imshow('2x2_grid', np.vstack([
    np.hstack([gray_img, blue_img]), 
    np.hstack([green_img, red_img])
]))
cv2.waitKey(0)
cv2.destroyWindow('2x2_grid')

Answer 6

color=(200, 100, 255) # sample of a color 
img = np.full((100, 100, 3), color, np.uint8)

Answer 7

对于8位(CV_8U)OpenCV映像,语法为:

Mat img(Mat(nHeight, nWidth, CV_8U);
img = cv::Scalar(50);    // or the desired uint8_t value from 0-255