
背景需求:
之前成功运用deepseek实现了透明背景PNG图片的主体图案的白色描边,在描边外延添加点状虚线
【教学类-102-03】自制剪纸图案(留白边、沿线剪)03——Python制作白色描边和黑点间隔(透明png图片)-优快云博客文章浏览阅读894次,点赞39次,收藏2次。【教学类-102-03】自制剪纸图案(留白边、沿线剪)03——Python制作白色描边和黑点间隔(透明png图片)
https://blog.youkuaiyun.com/reasonsummer/article/details/147002991?spm=1011.2415.3001.5331
在以上代码基础上,把点状虚线轮廓改为线条虚线轮廓

'''
剪纸外轮廓描边虚线制作(黑色虚线)沿线剪——平均边缘虚线的距离(最终效果)
deepseek 阿夏
20250405
修改为虚线版本
'''
from PIL import Image, ImageDraw
import os
import math
# 白边宽度(像素)
white_border_width = 30
# 虚线参数
dash_length = 20 # 每段虚线长度(像素)
dash_gap = 10 # 虚线间距(像素)
dash_width = 3 # 虚线粗细(像素)
def get_edge_pixels(image):
"""获取图像中不透明像素与透明像素交界的边缘像素坐标"""
edge_pixels = []
pixels = image.load()
width, height = image.size
for y in range(height):
for x in range(width):
if pixels[x, y][3] > 0: # 不透明像素
# 检查4邻域
for dx, dy in [(-1,0),(1,0),(0,-1),(0,1)]:
nx, ny = x+dx, y+dy
if 0 <= nx < width and 0 <= ny < height:
if pixels[nx, ny][3] == 0: # 邻域透明
edge_pixels.append((x, y))
break
return edge_pixels
def expand_edge_pixels(edge_pixels, distance, width, height):
"""扩展边缘像素坐标到指定距离"""
expanded_pixels = set()
for x, y in edge_pixels:
for dy in range(-distance, distance+1):
for dx in range(-distance, distance+1):
nx, ny = x+dx, y+dy
if 0 <= nx < width and 0 <= ny < height:
expanded_pixels.add((nx, ny))
return expanded_pixels
def get_contour_pixels(border_pixels, width, height):
"""获取白边区域的外轮廓像素(使用边缘追踪算法)"""
# 找到起始点(最左上角的边界像素)
start_point = None
for y in range(height):
for x in range(width):
if (x,y) in border_pixels:
start_point = (x,y)
break
if start_point:
break
if not start_point:
return []
# 使用Moore-Neighbor追踪算法获取轮廓
contour = []
current = start_point
previous = (current[0]-1, current[1]) # 假设从左侧开始
directions = [
(0, -1), (1, -1), (1, 0), (1, 1),
(0, 1), (-1, 1), (-1, 0), (-1, -1)
]
while True:
contour.append(current)
# 找到下一个边界点
found = False
start_dir = (directions.index((previous[0]-current[0], previous[1]-current[1])) + 1) % 8
for i in range(8):
dir_idx = (start_dir + i) % 8
dx, dy = directions[dir_idx]
neighbor = (current[0]+dx, current[1]+dy)
if 0 <= neighbor[0] < width and 0 <= neighbor[1] < height:
if neighbor in border_pixels:
previous = current