生成一张白色图片的算法--逻辑

　　

先生成一张黑色图，再用白色填充  

import numpy as np
import cv2  
#create a black use numpy,size is:512*512
img = np.zeros((512,512,3), np.uint8)   
#fill the image with white
img.fill(255)
###########################################
####Main Function                      #### 
#draw 
#        start x  y end x    y      color
cv2.line(img, (10,50), (511, 511), (255,0,0), 5) 
cv2.rectangle(img, (384,0), (510, 128), (0, 255, 0), 3)
cv2.circle(img, (447, 63), 63, (0,0,255), -1) 
cv2.ellipse(img, (256,256), (100,50),45,0,290,(0,0,255),-1)
font = cv2.FONT_HERSHEY_SIMPLEX  
cv2.putText(img, 'Hello', (10,500), font, 4, (255,2,255), 2)  
cv2.imshow('image', img)  
cv2.waitKey(0)  
cv2.destroyAllWindows()

　　

中文字符

import cv2
from PIL import Image, ImageDraw, ImageFont
import numpy as np

frame = np.zeros((512, 512, 3), np.uint8)
pil_img = Image.fromarray(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))  # 转化为pil 图片
draw = ImageDraw.Draw(pil_img)
font = ImageFont.truetype('simhei.ttf', 20, encoding="utf-8")
draw.text((50, 200), "中文字符ABC", (0, 0, 255), font)
frame = cv2.cvtColor(np.array(pil_img), cv2.COLOR_RGB2BGR)  # 转化为cv2 image
cv2.imwrite('my{}.jpg'.format(int(time.time())), frame)
os._exit(4232)