【Python实战】随机图像数据集自动生成（原创）_python randimage

一 、数据集介绍

如上图所示，数据集由一系列随机生成的图像组成，每幅图像包含了40~50个大小相等的“T"图案与一个”L"图案，它们在图像中的位置、方向都是无规则的，因此可以作为目标检测、语义分割等任务的数据集。

二、编程思路

1. 工具：使用turtle库进行绘图（可任意控制画笔的位置、朝向），使用random库生成随机数（调整字母图案的位置和角度）
2. 思路：字母图案逐行生成，行内各字母横向间隔随机，每行字母初始纵向间隔随机，各字母在生成时纵坐标都有随机微调。
3. 结构：1）生成一个“T”的函数和生成一个“L”的函数；2）主绘图函数：嵌套循环，内层循完成一次生成一行图案，外层循环完成则生成全部图案；3）转换图像格式、保存图像的函数

三、完整代码

import os
from turtle import *
from random import *
from PIL import Image
from PIL import EpsImagePlugin
from math import *

def draw_T(x, y, angle,color):# draw a 'T'
    pencolor(color)
    pensize(10)
    pu()# pen up: only move, no drawing
    goto(x, y)
    pd()# pen down: draw while moving
    setheading(angle)# change beginning direction
    forward(40)
    backward(20)
    left(90)# turn left
    forward(35)

def draw_L(x, y, angle,color):# draw an 'L' and record its info
    # draw an 'L'
    pencolor(color)
    pensize(10)
    long_side = 35 # first stroke
    short_side = 20 # second stroke
    pu()
    goto(x, y)
    pd()
    setheading(angle)
    forward(long_side)
    left(90)
    forward(short_side)
    
    # record its info
    sin_angle = sin(angle*pi/180)
    cos_angle = cos(angle*pi/180)
    long_sin = long_side*sin_angle
    long_cos = long_side*cos_angle
    short_sin = short_side*sin_angle
    short_cos = short_side*cos_angle
    
    x2 = long_cos + x # L's second point
    y2 = long_sin + y
    x3 = long_cos - short_sin +x # L's third point
    y3 = long_sin + short_cos + y
    x_right = max(x, x2, x3) + 9 # point of bounding box
    x_left = min(x, x2, x3) - 9
    y_top = max(y, y2, y3) + 9
    y_bottom = min(y, y2, y3) - 9
    Tran = 670/224 # The original image is 670*670 and we need 224*224.
    x_r = 112 + x_right // Tran # central coordinate system --> upper left coordinate system
    x_l = 112 + x_left // Tran
    y_t = 112 - y_top // Tran
    y_b = 112 - y_bottom // Tran
    
    show_bb(x_left,x_right,y_top,y_bottom) # show bounding box on the image
    
    with open('dataset/L_info.txt','a') as f: # store info of bounding box
        f.write('%d,%d,%d,%d\n' % (x_l,y_t,x_r,y_b))

def show_bb(x_left,x_right,y_top,y_bottom): # show bounding box on the image
    if choice == 'Y':
        pencolor('red')
        pensize(2)
        pu()
        goto(x_left,y_top)
        pd()
        goto(x_right,y_top)
        goto(x_right,y_bottom)
        goto(x_left,y_bottom)
        goto(x_left,y_top)

def paint_frame(): # draw background and frame(640*640)
    setup(670,670,0,0)# canvas size(670,670) and location(0,0)
    ht()# hide turtle(symbol of pen)
    tracer(0, 0)# speed up generation
    pencolor('black')
    pensize(10)
    pu()
    goto(-320,-320)
    pd()
    goto(-320,320)
    goto(320,320)
    goto(320,-320)
    goto(-320,-320)

def paint_dataset():# Draw line by line; set random small fluctuations
    paint_frame()
    # draw many T and one L
    num = 0# loop count
    for i in range(7):# 7 columns
        x = randint(-370,-350)# central coordinate system
        y = randint(-300,-280) + i * 90
        for j in range(6):# 6 raws
            x += randint(70,120)
            y += randint(-10,10)
            angle = randint(0,360)
            if num != DRAW_L:# DRAW_L is a random number decides when to draw 'L'
                if -280<x<300 and -280<y<290:# Remove 'T' which may be out of bounds.
                    draw_T(x, y, angle, 'black')# T's color is blue(0,0,255)
            else:
                draw_L(x, y, angle, 'black')# L's color is red(255,0,0)
            num += 1
    
def mkdir(path):# create folder
	folder = os.path.exists(path)
	if not folder:
		os.makedirs(path)           

def save_img(flodername1,flodername2,filename):# eps-->png(502*502)-->png(224*224)
    ts = getscreen().getcanvas()
    ts.postscript(file="%s/%s.eps" % (flodername1,filename))# save image as eps
    img1 = Image.open("%s/%s.eps" % (flodername1,filename))
    img1.save('%s/%s.png' % (flodername1,filename))# eps --> png
    img2 = img1.resize((224,224),Image.ANTIALIAS)
    img2.save('%s/%s.png' % (flodername2,filename))# 502*502 --> 224*224

def create(filename):# once creates one image and its ground_truth
    global DRAW_L # random number decides when to draw 'L'
    DRAW_L = randint(7,35)
    paint_dataset()
    save_img('temporary','dataset',filename)
    clear() # clean the canvas
    print('Finished: %d'%(int(filename)+1))

def generate():
    global filename # e.g.'1','2','3'...
    global choice
    if(os.path.exists('dataset/L_info.txt')):
        os.remove('dataset/L_info.txt') # delete old info
    for folder_name in ['temporary','dataset']:
        mkdir(folder_name)
    print('Tip: The window appears later can be minimized.')
    NUM = input('Please input the quantity of the dataset:\n')
    choice = input('Show the bounding box on images --- input "Y"\nOr generate an usable dataset --- input "N"\n').upper()
    for filename in range(int(NUM)):
        create(str(filename))
        os.remove('temporary/%s.eps'%filename) # Files in 'temporary' are useless.
        os.remove('temporary/%s.png'%filename)

if __name__ == '__main__':
    generate()

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

四、总结

1. 收获
   1）turtle库、random库的使用
   2）IO编程基本运用
   3）eps文件转png格式方法