地区种植蟒蛇

Question

我正在研究 python 中的区域增长算法实现。但是当我在输出上运行此代码时，我得到黑色图像，没有错误。在输入图像上使用 CV 阈值函数，对于种子值，我使用鼠标单击将 x,y 值存储在元组中。

def get8n(x, y, shape):
    out = []
    if y-1 > 0 and x-1 > 0:
        out.append( (y-1, x-1) )
    if y-1 > 0 :
        out.append( (y-1, x))
    if y-1 > 0 and x+1 < shape[1]:
        out.append( (y-1, x+1))
    if x-1 > 0:
        out.append( (y, x-1))
    if x+1 < shape[1]:
        out.append( (y, x+1))
    if y+1 < shape[0] and x-1 > 0:
        out.append( ( y+1, x-1))
    if y+1 < shape[0] :
        out.append( (y+1, x))
    if y+1 < shape[0] and x+1 < shape[1]:
       out.append( (y+1, x+1))
    return out

def region_growing(img, seed):
    list = []
    outimg = np.zeros_like(img)

    list.append((seed[0], seed[1]))
    while(len(list)):
        pix = list[0]
        outimg[pix[0], pix[1]] = 255
        for coord in get8n(pix[0], pix[1], img.shape):
            if img[coord[0], coord[1]] > 0:
                outimg[coord[0], coord[1]] = 255
                list.append((coord[0], coord[1]))
        list.pop(0)
    return outimg

def on_mouse(event, x, y, flags, params): 
    if event == cv2.EVENT_LBUTTONDOWN: 
        print 'Seed: ' + str(x) + ', ' + str(y) 
        clicks.append((y,x)) 

clicks = []
image = cv2.imread('lena.jpg', 0) 
ret, img = cv2.threshold(image, 200, 255, cv2.THRESH_BINARY) 
cv2.namedWindow('Input') 
cv2.setMouseCallback('Input', on_mouse, 0, ) 
cv2.imshow('Input', img) 
cv2.waitKey() 
seed = clicks[-1] 
cv2.imshow('Region Growing', region_growing(img, seed)) 
cv2.waitKey() 
cv2.destroyAllWindows()

Answer 1

我在使用你的 get8n() 函数时遇到了一些问题，所以我重写了它。我相信下面的代码可以满足您的要求。Region_Growing() 函数中有两行被注释掉。如果您取消注释它们，它们将显示处理过程中发生的情况的动画。这是可视化代码并让您了解哪里出了问题的好方法。

此外，在您的代码中，您可以将已处理的像素添加到“待处理”列表中。这导致了无限循环。我添加了一项检查，以防止已处理的像素被添加回列表中。

import cv2
import numpy as np

def get8n(x, y, shape):
    out = []
    maxx = shape[1]-1
    maxy = shape[0]-1
    
    #top left
    outx = min(max(x-1,0),maxx)
    outy = min(max(y-1,0),maxy)
    out.append((outx,outy))
    
    #top center
    outx = x
    outy = min(max(y-1,0),maxy)
    out.append((outx,outy))
    
    #top right
    outx = min(max(x+1,0),maxx)
    outy = min(max(y-1,0),maxy)
    out.append((outx,outy))
    
    #left
    outx = min(max(x-1,0),maxx)
    outy = y
    out.append((outx,outy))
    
    #right
    outx = min(max(x+1,0),maxx)
    outy = y
    out.append((outx,outy))
    
    #bottom left
    outx = min(max(x-1,0),maxx)
    outy = min(max(y+1,0),maxy)
    out.append((outx,outy))
    
    #bottom center
    outx = x
    outy = min(max(y+1,0),maxy)
    out.append((outx,outy))
    
    #bottom right
    outx = min(max(x+1,0),maxx)
    outy = min(max(y+1,0),maxy)
    out.append((outx,outy))
    
    return out

def region_growing(img, seed):
    seed_points = []
    outimg = np.zeros_like(img)
    seed_points.append((seed[0], seed[1]))
    processed = []
    while(len(seed_points) > 0):
        pix = seed_points[0]
        outimg[pix[0], pix[1]] = 255
        for coord in get8n(pix[0], pix[1], img.shape):
            if img[coord[0], coord[1]] != 0:
                outimg[coord[0], coord[1]] = 255
                if not coord in processed:
                    seed_points.append(coord)
                processed.append(coord)
        seed_points.pop(0)
        #cv2.imshow("progress",outimg)
        #cv2.waitKey(1)
    return outimg

def on_mouse(event, x, y, flags, params):
    if event == cv2.EVENT_LBUTTONDOWN:
        print 'Seed: ' + str(x) + ', ' + str(y), img[y,x]
        clicks.append((y,x))
        
clicks = []
image = cv2.imread('lena.bmp', 0)
ret, img = cv2.threshold(image, 128, 255, cv2.THRESH_BINARY)
cv2.namedWindow('Input')
cv2.setMouseCallback('Input', on_mouse, 0, )
cv2.imshow('Input', img)
cv2.waitKey()
seed = clicks[-1]
out = region_growing(img, seed)
cv2.imshow('Region Growing', out)
cv2.waitKey()
cv2.destroyAllWindows()

这是点击她帽子左侧的结果：