In my C project, im using OpenCV library to implement image processing algorithms. I want to draw outline or shadow to texts that i drew on frames with using OpenCV's putText function. I have researched about it but only solution that i found is drawing the same text twice. This solution drops the FPS of my overall project because im drawing many texts on the frames.

Do i have to code a new font library for my project or is there any simpler solutions to it?

thanks in advance.

EDIT: I tried FreeType with different ttf fonts that i found in various websites. Yes, there are some fonts that has default shadow or outlines in it. The problem here is i can't change the colour of the shadow of it. Yes, i can change the colour of overall font but shadow colour becomes the same as the font. I want black or white shadow that can highlight the text.

CodePudding user response：

You could use freetype. OpenCV can be compiled with FreeType which will allow you to load fonts from ttf files. then you can look up for a free font online which suits four needs of make your own ttf file.

Here is a link on how to use FreeType with opencv. https://docs.opencv.org/3.4/d9/dfa/classcv_1_1freetype_1_1FreeType2.html

CodePudding user response：

The simplest thing to do is draw the text once to an empty image, say A. then mask your main image several times with A, shifting A as required.