Overview & Basics

How to draw “stuff”?

The Painter class supports drawing onto existing images or a plain canvas. After setting up the canvas, use the Painter.draw_... methods.

Which “stuff” can be drawn?

`draw_arc()`	Draws a circular arc.
`draw_arrow()`	Draws an arrow.
`draw_bounding_box_2d()`	Draws a single 2D bounding box.
`draw_circle()`	Draws a circle.
`draw_ellipse()`	Draws an ellipse.
`draw_gradient()`	Draws a color gradient.
`draw_grid()`	Draws a grid.
`draw_horizon_line()`	Draws the estimated line of horizon.
`draw_image()`	Draws an image onto the canvas.
`draw_line()`	Draws a line.
`draw_marker()`	Draws a single marker/keypoint.
`draw_markers()`	Draws multiple (similarly styled) markers/keypoints.
`draw_polygon()`	Draws a polygon.
`draw_rect()`	Draws a rectangle.
`draw_text()`	Draws single- or multi-line text.
`draw_text_box()`	Draws a single- or multi-line text box.
`draw_trajectories()`	Draws multiple (similarly styled) trajectories.
`draw_trajectory()`	Draws a single trajectory.
`draw_xyz_axes()`	Visualizes a coordinate system reference frame.
`reset_clip()`	Resets the latest clip region.
`set_clip_circle()`	Establishes a circular clip region for the current canvas.
`set_clip_rect()`	Establishes a rectangular clip region for the current canvas.

What about visualizations besides drawing?

Besides drawing, viren2d also provides various color maps and colorization techniques to inspect and represent data, such as depth measurements, topographic data, gradient or flow fields, etc.

Additionally, the ImageBuffer provides some basic image processing functionalities, e.g. to blend/overlay images, pixelate() regions, some general color space conversions, etc. Note, however, that these functionalities are only provided for user convenience and are not optimized towards high-speed, i.e. viren2d does not use OpenMP, oneTBB, AVX, Neon or any other multi-threading/multi-processing extensions.

Which coordinate system is used?

All coordinates assume an image coordinate system, where the origin (0, 0) is at the top left corner, the positive \(x\) axis is pointing right and the positive \(y\) axis is pointing down.

How to specify angles?

Unless stated otherwise in the corresponding API documentation, all angle measurements are assumed to be in degrees. The rotation direction for positive angles is from the positive \(x\) axis towards the positive \(y\) axis.