src/plot_utils.py

import numpy as np
import matplotlib.pyplot as plt


def show_mask(mask, ax, random_color=False, borders=True):
    if random_color:
        color = np.concatenate([np.random.random(3), np.array([0.6])], axis=0)
    else:
        color = np.array([30 / 255, 144 / 255, 255 / 255, 0.6])
    h, w = mask.shape[-2:]
    mask = mask.astype(np.uint8)
    mask_image = mask.reshape(h, w, 1) * color.reshape(1, 1, -1)
    if borders:
        import cv2

        contours, _ = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
        # Try to smooth contours
        contours = [
            cv2.approxPolyDP(contour, epsilon=0.01, closed=True) for contour in contours
        ]
        mask_image = cv2.drawContours(
            mask_image, contours, -1, (1, 1, 1, 0.5), thickness=2
        )
    ax.imshow(mask_image)


def show_points(coords, labels, ax, marker_size=375):
    pos_points = coords[labels == 1]
    neg_points = coords[labels == 0]
    ax.scatter(
        pos_points[:, 0],
        pos_points[:, 1],
        color="green",
        marker="*",
        s=marker_size,
        edgecolor="white",
        linewidth=1.25,
    )
    ax.scatter(
        neg_points[:, 0],
        neg_points[:, 1],
        color="red",
        marker="*",
        s=marker_size,
        edgecolor="white",
        linewidth=1.25,
    )


def show_box(box, ax):
    x0, y0 = box[0], box[1]
    w, h = box[2] - box[0], box[3] - box[1]
    ax.add_patch(
        plt.Rectangle((x0, y0), w, h, edgecolor="green", facecolor=(0, 0, 0, 0), lw=2)
    )


def show_masks(
    image,
    masks,
    scores,
    point_coords=None,
    box_coords=None,
    input_labels=None,
    borders=True,
):
    num_masks = len(masks)
    num_cols = num_masks  # Number of columns is equal to the number of masks

    fig, axes = plt.subplots(1, num_cols, figsize=(5 * num_cols, 5))

    if num_masks == 1:
        axes = [axes]  # Ensure axes is iterable when there's only one mask

    for i, (mask, score) in enumerate(zip(masks, scores)):
        ax = axes[i]

        ax.imshow(image)
        show_mask(mask, ax, borders=borders)
        if point_coords is not None:
            assert input_labels is not None
            show_points(point_coords, input_labels, ax)
        if box_coords is not None:
            show_box(box_coords, ax)
        if len(scores) > 1:
            ax.set_title(f"Mask {i+1}, Score: {score:.3f}", fontsize=18)
        ax.axis("off")

    plt.tight_layout()
    return plt