Function plot_matches

hloc/utils/viz.py:70–109

Plot matches for a pair of existing images. Args: kpts0, kpts1: corresponding keypoints of size (N, 2). color: color of each match, string or RGB tuple. Random if not given. lw: width of the lines. ps: size of the end points (no endpoint if ps=0) indices:

(kpts0, kpts1, color=None, lw=1.5, ps=4, indices=(0, 1), a=1.)

def plot_matches(kpts0, kpts1, color=None, lw=1.5, ps=4, indices=(0, 1), a=1.):
    """Plot matches for a pair of existing images.
    Args:
        kpts0, kpts1: corresponding keypoints of size (N, 2).
        color: color of each match, string or RGB tuple. Random if not given.
        lw: width of the lines.
        ps: size of the end points (no endpoint if ps=0)
        indices: indices of the images to draw the matches on.
        a: alpha opacity of the match lines.
    """
    fig = plt.gcf()
    ax = fig.axes
    assert len(ax) > max(indices)
    ax0, ax1 = ax[indices[0]], ax[indices[1]]
    fig.canvas.draw()

    assert len(kpts0) == len(kpts1)
    if color is None:
        color = matplotlib.cm.hsv(np.random.rand(len(kpts0))).tolist()
    elif len(color) > 0 and not isinstance(color[0], (tuple, list)):
        color = [color] * len(kpts0)

    if lw > 0:
        # transform the points into the figure coordinate system
        transFigure = fig.transFigure.inverted()
        fkpts0 = transFigure.transform(ax0.transData.transform(kpts0))
        fkpts1 = transFigure.transform(ax1.transData.transform(kpts1))
        fig.lines += [matplotlib.lines.Line2D(
            (fkpts0[i, 0], fkpts1[i, 0]), (fkpts0[i, 1], fkpts1[i, 1]),
            zorder=1, transform=fig.transFigure, c=color[i], linewidth=lw,
            alpha=a)
            for i in range(len(kpts0))]

    # freeze the axes to prevent the transform to change
    ax0.autoscale(enable=False)
    ax1.autoscale(enable=False)

    if ps > 0:
        ax0.scatter(kpts0[:, 0], kpts0[:, 1], c=color, s=ps)
        ax1.scatter(kpts1[:, 0], kpts1[:, 1], c=color, s=ps)


def add_text(idx, text, pos=(0.01, 0.99), fs=15, color='w',