Source code for detectron2.utils.colormap

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.

"""
An awesome colormap for really neat visualizations.
Copied from Detectron, and removed gray colors.
"""

import numpy as np

__all__ = ["colormap", "random_color"]

# fmt: off
# RGB:
_COLORS = np.array(
    [
        0.000, 0.447, 0.741,
        0.850, 0.325, 0.098,
        0.929, 0.694, 0.125,
        0.494, 0.184, 0.556,
        0.466, 0.674, 0.188,
        0.301, 0.745, 0.933,
        0.635, 0.078, 0.184,
        0.300, 0.300, 0.300,
        0.600, 0.600, 0.600,
        1.000, 0.000, 0.000,
        1.000, 0.500, 0.000,
        0.749, 0.749, 0.000,
        0.000, 1.000, 0.000,
        0.000, 0.000, 1.000,
        0.667, 0.000, 1.000,
        0.333, 0.333, 0.000,
        0.333, 0.667, 0.000,
        0.333, 1.000, 0.000,
        0.667, 0.333, 0.000,
        0.667, 0.667, 0.000,
        0.667, 1.000, 0.000,
        1.000, 0.333, 0.000,
        1.000, 0.667, 0.000,
        1.000, 1.000, 0.000,
        0.000, 0.333, 0.500,
        0.000, 0.667, 0.500,
        0.000, 1.000, 0.500,
        0.333, 0.000, 0.500,
        0.333, 0.333, 0.500,
        0.333, 0.667, 0.500,
        0.333, 1.000, 0.500,
        0.667, 0.000, 0.500,
        0.667, 0.333, 0.500,
        0.667, 0.667, 0.500,
        0.667, 1.000, 0.500,
        1.000, 0.000, 0.500,
        1.000, 0.333, 0.500,
        1.000, 0.667, 0.500,
        1.000, 1.000, 0.500,
        0.000, 0.333, 1.000,
        0.000, 0.667, 1.000,
        0.000, 1.000, 1.000,
        0.333, 0.000, 1.000,
        0.333, 0.333, 1.000,
        0.333, 0.667, 1.000,
        0.333, 1.000, 1.000,
        0.667, 0.000, 1.000,
        0.667, 0.333, 1.000,
        0.667, 0.667, 1.000,
        0.667, 1.000, 1.000,
        1.000, 0.000, 1.000,
        1.000, 0.333, 1.000,
        1.000, 0.667, 1.000,
        0.333, 0.000, 0.000,
        0.500, 0.000, 0.000,
        0.667, 0.000, 0.000,
        0.833, 0.000, 0.000,
        1.000, 0.000, 0.000,
        0.000, 0.167, 0.000,
        0.000, 0.333, 0.000,
        0.000, 0.500, 0.000,
        0.000, 0.667, 0.000,
        0.000, 0.833, 0.000,
        0.000, 1.000, 0.000,
        0.000, 0.000, 0.167,
        0.000, 0.000, 0.333,
        0.000, 0.000, 0.500,
        0.000, 0.000, 0.667,
        0.000, 0.000, 0.833,
        0.000, 0.000, 1.000,
        0.000, 0.000, 0.000,
        0.143, 0.143, 0.143,
        0.857, 0.857, 0.857,
        1.000, 1.000, 1.000
    ]
).astype(np.float32).reshape(-1, 3)
# fmt: on


[docs]def colormap(rgb=False, maximum=255): """ Args: rgb (bool): whether to return RGB colors or BGR colors. maximum (int): either 255 or 1 Returns: ndarray: a float32 array of Nx3 colors, in range [0, 255] or [0, 1] """ assert maximum in [255, 1], maximum c = _COLORS * maximum if not rgb: c = c[:, ::-1] return c
[docs]def random_color(rgb=False, maximum=255): """ Args: rgb (bool): whether to return RGB colors or BGR colors. maximum (int): either 255 or 1 Returns: ndarray: a vector of 3 numbers """ idx = np.random.randint(0, len(_COLORS)) ret = _COLORS[idx] * maximum if not rgb: ret = ret[::-1] return ret
if __name__ == "__main__": import cv2 size = 100 H, W = 10, 10 canvas = np.random.rand(H * size, W * size, 3).astype("float32") for h in range(H): for w in range(W): idx = h * W + w if idx >= len(_COLORS): break canvas[h * size : (h + 1) * size, w * size : (w + 1) * size] = _COLORS[idx] cv2.imshow("a", canvas) cv2.waitKey(0)