Visualization

Color wheel (default)

img = fz.colorize(flow)                       # per-frame max normalization
img = fz.colorize(flow, max_flow=20.0)        # fixed normalizer
img = fz.colorize(flow, legend=True)          # embed the color-wheel key
img = fz.colorize(flow, convention="hsv")     # alternative encoding

flowiz's color wheel is bit-compatible (±1 LSB) with the widely used flow_vis package, so figures match across the literature. This is enforced by parity tests against an independent reference implementation.

Temporally consistent video

Per-frame normalization makes videos flicker. Normalize by the whole sequence:

frames = fz.colorize_sequence(flows, max_flow="sequence")   # shared normalizer

flowiz video does this by default.

Alternative encodings

fz.flow_to_uv(flow)          # (H, W, 2) normalized u/v channels
fz.flow_to_magnitude(flow)   # magnitude heatmap (magma)
fz.flow_to_angle(flow)       # direction map (hue)

Vector overlays

img = fz.quiver(flow, step=16, scale=1.0)                 # arrows on the color map
img = fz.quiver(flow, background=my_rgb_frame, step=24)   # arrows on any image

Color-wheel legend

legend = fz.wheel_legend(128)   # (128, 128, 4) RGBA, transparent outside the disk