Load TrueType Font to OpenCV

Question

Can we load a custom TrueType font and use it with cv2.putText function ?

font = cv2.FONT_HERSHEY_SIMPLEX cv2.putText(img,'OpenCV',(10,500), font, 4,(255,255,255),2,cv2.LINE_AA) 

Answer 1

In OpenCV, only a subset of Hershey fonts are supported.

In opencv2/core.hpp, you can find this enum HersheyFonts.

//! Only a subset of Hershey fonts enum HersheyFonts {     FONT_HERSHEY_SIMPLEX        = 0, //!< normal size sans-serif font     FONT_HERSHEY_PLAIN          = 1, //!< small size sans-serif font     FONT_HERSHEY_DUPLEX         = 2, //!< normal size sans-serif font (more complex than FONT_HERSHEY_SIMPLEX)     FONT_HERSHEY_COMPLEX        = 3, //!< normal size serif font     FONT_HERSHEY_TRIPLEX        = 4, //!< normal size serif font (more complex than FONT_HERSHEY_COMPLEX)     FONT_HERSHEY_COMPLEX_SMALL  = 5, //!< smaller version of FONT_HERSHEY_COMPLEX     FONT_HERSHEY_SCRIPT_SIMPLEX = 6, //!< hand-writing style font     FONT_HERSHEY_SCRIPT_COMPLEX = 7, //!< more complex variant of FONT_HERSHEY_SCRIPT_SIMPLEX     FONT_ITALIC                 = 16 //!< flag for italic font }; 

You can try PIL.ImageFont if you want to use custom font.

A basic example is presented here:

import numpy as np from PIL import ImageFont, ImageDraw, Image import cv2 import time  ## Make canvas and set the color img = np.zeros((200,400,3),np.uint8) b,g,r,a = 0,255,0,0  ## Use cv2.FONT_HERSHEY_XXX to write English. text = time.strftime("%Y/%m/%d %H:%M:%S %Z", time.localtime())  cv2.putText(img,  text, (50,50), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (b,g,r), 1, cv2.LINE_AA)  ## Use simsum.ttc to write Chinese. fontpath = "./simsun.ttc"      font = ImageFont.truetype(fontpath, 32) img_pil = Image.fromarray(img) draw = ImageDraw.Draw(img_pil) draw.text((50, 100),  "国庆节/中秋节 快乐!", font = font, fill = (b, g, r, a)) img = np.array(img_pil)  ## Display  cv2.imshow("res", img);cv2.waitKey();cv2.destroyAllWindows() cv2.imwrite("res.png", img)