nlc.py 文件源码

def color_hist(im, colBins):
    """
    Get color histogram descriptors for RGB and LAB space.
    Input: im: (h,w,c): 0-255: np.uint8: RGB
    Output: descriptor: (colBins*6,)
    """
    assert im.ndim == 3 and im.shape[2] == 3, "image should be rgb"
    arr = np.concatenate((im, color.rgb2lab(im)), axis=2).reshape((-1, 6))
    desc = np.zeros((colBins * 6,), dtype=np.float)
    for i in range(3):
        desc[i * colBins:(i + 1) * colBins], _ = np.histogram(
            arr[:, i], bins=colBins, range=(0, 255))
        desc[i * colBins:(i + 1) * colBins] /= np.sum(
            desc[i * colBins:(i + 1) * colBins]) + (
            np.sum(desc[i * colBins:(i + 1) * colBins]) < 1e-4)
    i += 1
    desc[i * colBins:(i + 1) * colBins], _ = np.histogram(
        arr[:, i], bins=colBins, range=(0, 100))
    desc[i * colBins:(i + 1) * colBins] /= np.sum(
        desc[i * colBins:(i + 1) * colBins]) + (
        np.sum(desc[i * colBins:(i + 1) * colBins]) < 1e-4)
    for i in range(4, 6):
        desc[i * colBins:(i + 1) * colBins], _ = np.histogram(
            arr[:, i], bins=colBins, range=(-128, 127))
        desc[i * colBins:(i + 1) * colBins] /= np.sum(
            desc[i * colBins:(i + 1) * colBins]) + (
            np.sum(desc[i * colBins:(i + 1) * colBins]) < 1e-4)
    return desc