Merge pull request #21 from segment-oj/improve-captcha-ztl

Improve captcha ztl

Author: szdytom

captcha/FiraCode-Regular.ttf

@@ -1,5 +1,7 @@
 from django.apps import AppConfig
+from django.conf import settings
 
+import os.path
 
 class CaptchaConfig(AppConfig):
     name = 'captcha'
@@ -16,7 +18,7 @@ class CaptchaConfig(AppConfig):
     # try it until you find the best value
     font_size = 30
     # the font file of font
-    font_family = "/usr/share/fonts/truetype/noto/NotoMono-Regular.ttf"
+    font_family = os.path.join(settings.BASE_DIR, "captcha", "FiraCode-Regular.ttf")
     # The number of dots on the pic to interfare
     dot_number = 100
     # The number of lines on the pic to interfare

captcha/apps.py

@@ -1,3 +1,63 @@
 from django.test import TestCase
+from captcha.tools import GenCaptcha
 
 # Create your tests here.
+class GenCaptchaTest(TestCase):
+    # set up test
+    def setUp(self):
+        self.captcha = GenCaptcha()
+
+    def testZ_get_random_color(self):
+        for i in range(1, 1000):
+            color = self.captcha.getRandomColor()
+            
+            r = color[0]
+            g = color[1]
+            b = color[2]
+
+            r_in_range = r >= 0 and r <= 255
+            g_in_range = g >= 0 and g <= 255
+            b_in_range = b >= 0 and b <= 255
+
+            resault = r_in_range and g_in_range and b_in_range
+
+            self.assertTrue(resault)
+
+    def testY_get_random_char(self):
+        for i in range(1, 1000):
+            random_char = self.captcha.getRandomChar()
+
+            is_number = random_char >= "0" and random_char <= "9"
+            is_upper = random_char >= "A" and random_char <= "Z"
+            is_lower = random_char >= "a" and random_char <= "z"
+
+            is_char = is_number or is_lower or is_upper
+
+            is_o = random_char == 'o' or random_char == 'O'
+
+            resault =  is_char and not is_o
+
+            self.assertTrue(resault)
+
+    def testX_check_similarity_false_far(self):
+        color1 = (0, 0, 0)
+        color2 = (255, 255, 255)
+
+        self.assertFalse(self.captcha.checkSimilarity(color1, color2))
+
+    def testW_check_similarity_false_close(self):
+        color1 = (249, 244, 217)
+        color2 = (69, 157, 245)
+
+        self.assertFalse(self.captcha.checkSimilarity(color1, color2))
+
+    def testV_check_similarity_same(self):
+        color = (56, 1, 31)
+
+        self.assertTrue(self.captcha.checkSimilarity(color, color))
+
+    def testU_check_similarity_true(self):
+        color1 = (69, 157, 245)
+        color2 = (70, 158, 246)
+
+        self.assertTrue(self.captcha.checkSimilarity(color1, color2))

captcha/tests.py

@@ -3,6 +3,7 @@
 from django.utils import timezone
 import datetime
 import random
+import math
 from PIL import Image, ImageDraw, ImageFont
 
 from .apps import CaptchaConfig
@@ -33,8 +34,15 @@ def getRandomColor(self):
     def getRandomChar(self):
         random_num = str(random.randint(0, 9))       # numbers
         random_lower = chr(random.randint(97, 122))  # lower case letters
-        random_upper = chr(random.randint(65, 90))   # upper case letters 
+        random_upper = chr(random.randint(65, 90))   # upper case letters
+
+        while random_lower == 'o':
+            random_lower = chr(random.randint(97, 122))
+        while random_upper == 'O':
+            random_upper = chr(random.randint(65, 90))
+
         random_char = random.choice([random_num, random_lower, random_upper])
+
         return random_char
 
     # draw random lines to interfere
@@ -57,6 +65,30 @@ def drawPoint(self, draw):
             y = random.randint(0, self.height)
             draw.point((x,y), fill = self.getRandomColor())
 
+    def checkSimilarity(self, color1, color2):
+        r1 = color1[0]
+        g1 = color1[1]
+        b1 = color1[2]
+
+        r2 = color2[0]
+        g2 = color2[1]
+        b2 = color2[2]
+
+        r3 = (r1 - r2) / 256
+        g3 = (g1 - g2) / 256
+        b3 = (b1 - b2) / 256
+
+        color_diff = math.sqrt(r3 ** 2 + g3 ** 2 + b3 ** 2)
+
+        bright1 = ((r1 * 299) + (g1 * 587) + (b1 * 114))
+        bright2 = ((r2 * 299) + (g2 * 587) + (b2 * 114))
+
+        bright_diff = abs(bright1 - bright2)
+
+        if color_diff < 0.7 or bright_diff < 100 * 255:
+            return True
+        return False
+
     # create random picture
     # @param -> img save path
     # @return -> answer
@@ -79,7 +111,7 @@ def createImg(self, path):
             random_txt = self.getRandomChar()
             txt_color = self.getRandomColor()
             # avoid the text color is same to background color
-            while txt_color == bg_color:
+            while self.checkSimilarity(bg_color, txt_color):
                 txt_color = self.getRandomColor()
 
             # draw text