- Mastering OpenCV 4 with Python
- Alberto Fernández Villán
- 164字
- 2025-04-04 14:41:18
Understanding advanced shapes
In this section, we are going to see how to draw clip lines, arrowed lines, ellipses, and polylines. These shapes are not as straightforward to draw as the shapes we saw in the previous section, but they are simple to understand. The first step is to create an image where the shapes will be drawn. For this, a 300 300 image with the 3 channels (to properly display a BGR image) and a uint8 type (8-bit unsigned integers) will be created:
# We create the canvas to draw: 300 x 300 pixels, 3 channels, uint8 (8-bit unsigned integers)
# We set the background to black using np.zeros()
image = np.zeros((300, 300, 3), dtype="uint8")
We set the background to light gray using the colors dictionary:
# If you want another background color, you can do the following:
image[:] = colors['light_gray']
At this point, we can start drawing the new shapes.