Fix captcha part 1: more human readable (but less cool)

captcha.py

@@ -1,20 +1,10 @@
-import os
 import random
+import string
 
-import numpy
-import pylab
 from PIL import Image, ImageDraw, ImageFont
-import mpl_toolkits.mplot3d.axes3d as axes3d
-import io
-from wand.image import Image as WImage
 from flask import request, session
 
 import config
-from common import logger
-
-SIZE = (60, 20)
-with open("words.txt") as f:
-    WORDS = f.read().splitlines(keepends=False)
 
 
 def get_code():
@@ -51,41 +41,175 @@ def verify():
     return False
 
 
+cfg = {
+    "image": {
+        "size": (200, 72),
+        "supersampling": 2
+    },
+    "noise": {
+        "min": 100,
+        "max": 250
+    },
+    "colors": {
+        "green": [(1, 51, 1), (34, 204, 34)],
+        "yellow": [(67, 67, 1), (221, 221, 0)],
+        "cyan": [(17, 51, 85), (85, 187, 254)],
+        "magenta": [(51, 1, 51), (254, 0, 254)],
+        "red": [(67, 1, 1), (254, 68, 68)],
+        "orange": [(68, 51, 1), (255, 153, 0)]
+    },
+    "lines": {
+        "back_thin": {"n": 3, "w": 5},
+        "back_thick": {"n": 3, "w": 6},
+        "back_positions": [
+            {
+                "ax": (0, 10),
+                "ay": (0, 36),
+                "bx": (150, 200),
+                "by": (18, 50)
+            },
+            {
+                "ax": (0, 10),
+                "ay": (18, 50),
+                "bx": (150, 200),
+                "by": (0, 17)
+            }
+        ],
+        "front_horizontal_thin": {"n": 2, "w": 3},
+        "front_horizontal_thick": {"n": 2, "w": 4},
+        "front_horizontal_positions": [
+            {
+                "ax": (0, 20),
+                "ay": (0, 34),
+                "bx": (150, 200),
+                "by": (18, 50)
+            },
+            {
+                "ax": (0, 20),
+                "ay": (18, 72),
+                "bx": (140, 200),
+                "by": (0, 36)
+            },
+        ],
+        "front_vertical": {"n": 2, "w": 4},
+        "front_vertical_positions": {
+            "outside": 5,
+            "font_width": 13,
+            "ay": (0, 16),
+            "by": (54, 72)
+        }
+    },
+    "text": {
+        "font": {
+            "path": "static/Hack-Regular.ttf",
+            "size": 60,
+            "outline": [1, 2]
+        },
+        "letters": {
+            "3": {
+                "count": 3,
+                "x_min": 35,
+                "x_max": 50,
+                "y_min": -5,
+                "y_max": 8
+            },
+            "4": {
+                "count": 4,
+                "x_min": 20,
+                "x_max": 35,
+                "y_min": -5,
+                "y_max": 8
+            },
+            "5": {
+                "count": 5,
+                "x_min": 5,
+                "x_max": 20,
+                "y_min": -5,
+                "y_max": 8
+            }
+        }
+    }
+}
+
+size = cfg["image"]["size"]
+c = cfg["image"]["supersampling"]
+
+# Additional config
+letter_count = "4"
+
+
+def horizontal_lines(draw, c, line_par, line_pos, fill):
+    for _ in range(line_par["n"]):
+        pos = random.randrange(0, len(line_pos))
+        ax = random.randint(*line_pos[pos]["ax"])
+        ay = random.randint(*line_pos[pos]["ay"])
+        bx = random.randint(*line_pos[pos]["bx"])
+        by = random.randint(*line_pos[pos]["by"])
+        draw.line([(ax*c, ay*c), (bx*c, by*c)], width=line_par["w"]*c, fill=fill)
+
+
 def make_captcha():
-    word = random.choice(WORDS)
-    path = get_path(word)
 
-    logger.info("generating CAPTCHA: " + word)
+    color_name, color = random.choice(list(cfg["colors"].items()))
+    text = ''.join(random.choices(string.ascii_uppercase + string.digits, k=cfg["text"]["letters"][letter_count]["count"]))
 
-    if os.path.exists(path):
+    path = get_path(text)
-        os.remove(path)
 
-    image = Image.new('L', SIZE, 255)
+    w = size[0]*c
-    image_draw = ImageDraw.Draw(image)
+    h = size[1]*c
-    font = ImageFont.truetype("static/Hack-Regular.ttf", 12)
 
-    image_draw.text((5, 3), word, font=font)
+    img = Image.new('RGB', (w, h))
+    pixels = img.load()
 
-    x, y = numpy.meshgrid(range(SIZE[0]), range(SIZE[1]))
+    # noise
-    z = 1 - numpy.asarray(image) / 255
+    for x in range(w):
+        for y in range(h):
+            rcol = random.randint(cfg["noise"]["min"], cfg["noise"]["max"])
+            pixels[x, y] = (rcol, rcol, rcol)
 
-    fig = pylab.figure()
+    # background lines
-    ax = axes3d.Axes3D(fig)
+    draw = ImageDraw.Draw(img)
-    ax.plot_wireframe(x, -y, z, rstride=1, cstride=1)
-    ax.set_zlim((0, 20))
-    ax.set_axis_off()
-    pylab.close(fig)
 
-    buf = io.BytesIO()
+    horizontal_lines(draw, c, cfg["lines"]["back_thin"], cfg["lines"]["back_positions"], color[0])
-    fig.savefig(buf, dpi=150)
+    horizontal_lines(draw, c, cfg["lines"]["back_thick"], cfg["lines"]["back_positions"], color[0])
-    buf.seek(0)
-    image.close()
 
-    with WImage(blob=buf.read()) as img:
+    # text
-        img.trim()
+    ctx = cfg["text"]["font"]
-        img.save(filename=path)
+    font = ImageFont.truetype(ctx["path"], ctx["size"]*c)
+    outline = random.choice(ctx["outline"])
 
-    return word
+    ctx = cfg["text"]["letters"][letter_count]
+    x = random.randint(ctx["x_min"], ctx["x_max"])
+    y = random.randint(ctx["y_min"], ctx["y_max"])
+    draw.text((x*c-outline*c, y*c-outline*c), text, color[0], font=font)
+    draw.text((x*c-outline*c, y*c), text, color[0], font=font)
+    draw.text((x*c-outline*c, y*c+outline*c), text, color[0], font=font)
+    draw.text((x*c, y*c-outline*c), text, color[0], font=font)
+    draw.text((x*c, y*c+outline*c), text, color[0], font=font)
+    draw.text((x*c+outline*c, y*c-outline*c), text, color[0], font=font)
+    draw.text((x*c+outline*c, y*c), text, color[0], font=font)
+    draw.text((x*c+outline*c, y*c+outline*c), text, color[0], font=font)
+    draw.text((x*c, y*c), text, color[1], font=font)
+
+    # foreground lines
+    horizontal_lines(draw, c, cfg["lines"]["front_horizontal_thin"], cfg["lines"]["front_horizontal_positions"], color[1])
+    horizontal_lines(draw, c, cfg["lines"]["front_horizontal_thick"], cfg["lines"]["front_horizontal_positions"], color[1])
+
+    # vertical lines
+    line_par = cfg["lines"]["front_vertical"]
+    line_pos = cfg["lines"]["front_vertical_positions"]
+
+    for _ in range(line_par["n"]):
+        ax = random.randint(x-line_pos["outside"], x+line_pos["outside"] + cfg["text"]["letters"][letter_count]["count"]*line_pos["font_width"])
+        bx = ax + random.randint(-line_pos["font_width"], line_pos["font_width"])
+        ay = random.randint(*line_pos["ay"])
+        by = random.randint(*line_pos["by"])
+        draw.line([(ax*c, ay*c), (bx*c, by*c)], width=line_par["w"]*c, fill=color[1])
+
+    img.thumbnail(cfg["image"]["size"], Image.ANTIALIAS)
+    img.save(path, "png")
+
+    return text
 
 
 if __name__ == "__main__":