OpenCV：利用python-cv2绘制图形

1.绘制线段

cv2.line(img, pt1, pt2, color, thickness, lineType):

-img: 目标图像
-pt1: 起点
-pt2: 终点
-color: 绘制的颜色
-thickness: 线段宽度
-lineType: 线段类型

import cv2
import numpy as np
newImageInfo = (200,200,3)
dat = np.zeros(newImageInfo, np.uint8)
# 绘制线段 1.目标图像 2.begin 3.end 4.color
cv2.line(dat, (0,0), (200, 200), (0,,255))
cv2.line(dat, (50, 100), (150, 100), (0,255,255), 20)
cv2.imshow('dat', dat)
cv2.waitKey(0)

2.绘制矩形、圆形和椭圆

cv2.rectangle(img, pt1, pt2, color,thickness,lineType)

cv2.circle(img, center, radius, color,thickness,lineType

cv2.ellipse(mg, center, axes, angle, startAngle, endAngle, color,thickness,lineType)

cv2.ellipse?

import cv2
import numpy as np
newImageInfo = (200,200,3)
dat = np.zeros(newImageInfo, np.uint8)
# -1表示填充
cv2.rectangle(dat, (50,50), (150, 150), (0, 255, 0), -1) 
# 2.center 3 半径 4 color 
cv2.circle(dat, (100,100), (25), (0,0,255),2)
# 1.图像 2 圆心 3 轴 4 角度 5 起始角度 6 终止角度 7 颜色 8宽度
cv2.ellipse(dat,(100,100), (50,25),0,0,360,(255,0,0),2)
cv2.imshow('dat', dat)
cv2.waitKey(0)

3.绘制任意多边形

cv2.polylines(img, pts, isClosed, color,thickness,lineType)

import cv2
import numpy as np
newImageInfo = (200,200,3)
dat = np.zeros(newImageInfo, np.uint8)

points = np.array([[25,25], [50, 25], [25, 75], [150, 175], [100, 75]], np.int32)
points = points.reshape((-1, 1, 2))
cv2.polylines(dat, [points], True, (0,255,255))
cv2.imshow('dat', dat)
cv2.waitKey(0)

4.文字图片绘制

绘制文字

cv2.putText(img, text, org, fontFace, fontScale, color,thickness,lineType)

import cv2
import numpy as np
img = cv2.imread('img.jpg', 1)
font = cv2.FONT_HERSHEY_SIMPLEX

#2 text 3 坐标起点 4 字体类型 5 字体大小 6 颜色 7粗细 8 linetype
cv2.putText(img,"this is flower",(100, 160), font, 1, (200,100,255),2,cv2.LINE_AA)
cv2.imshow('img', img)
cv2.waitKey(0)

绘制图片

import cv2
import numpy as np
img = cv2.imread('img.jpg', 1)
height = int(img.shape[0] * 0.3)
width = int(img.shape[1] * 0.3)
imgResize = cv2.resize(img, (width, height))
for i in range(height):
    for j in range(width):
        img[i + 125, j + 125] = imgResize[i, j]
cv2.imshow('img', img)
cv2.waitKey(0)