如何从图像中获取有序路径列表？

Question

我们有 100x100 像素的图像。在此图像中，红线是一条路径。当我将此图像解析为像素颜色时，我以随机顺序获得红色像素（实际上，我从图像中从上到下逐行获取像素）。但我想要获得从 A 点到 B 点的路径的有序点列表。如何做到这一点。

图像中的路径示例

该函数获取红色像素（Python语言）：

def getRoad(imgPng) -> list:
    img = Image.open(imgPng)
    pix = img.load()
    width, height = img.size

    x = 0
    y = 0
    road = []

    for y in range(BORDER_OFFSET, height-BORDER_OFFSET, STEP):
        for x in range(BORDER_OFFSET, width-BORDER_OFFSET, STEP):
            color = pix[x, y]
            if (COLOR_ROAD[0]-7 <= color[0] <= COLOR_ROAD[0]+7 and 
            COLOR_ROAD[1]-7 <= color[1] <= COLOR_ROAD[1]+7 and
            COLOR_ROAD[2]-7 <= color[2] <= COLOR_ROAD[2]+7):
                road.append((x, y))

    # print(len(road))
    return road

Answer 1

您可以通过首先收集所有红色像素，然后根据它们彼此的接近程度对它们进行排序，来提取图像中的红色路径并对其进行排序。下面的代码演示了如何在 Python 中使用

PIL

图像处理库和简单的基于距离的排序算法来实现此目的。

from PIL import Image
import math

def get_road(imgPng):
    img = Image.open(imgPng)
    pix = img.load()
    width, height = img.size

    road = []
    for y in range(height):
        for x in range(width):
            color = pix[x, y]
            if (230 <= color[0] <= 255 and 0 <= color[1] <= 50 and 0 <= color[2] <= 50):
                road.append((x, y))

    return road

def distance(point1, point2):
    return math.sqrt((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2)

def order_points(points, max_jump=50):
    ordered = [points.pop(0)]
    while points:
        last = ordered[-1]
        next_point = min(points, key=lambda point: distance(last, point))
        if distance(last, next_point) > max_jump:
            break
        points.remove(next_point)
        ordered.append(next_point)
    return ordered

road_points = get_road('./image.png')
ordered_road_points = order_points(road_points)

print(ordered_road_points)