创建空白图
def plain_white(height, width): return Image.new("L", (width, height), 255).convert("RGBA")
背景加高斯噪声。
def gaussian_noise(height, width): # 创建一个白色图 image = np.ones((height, width)) * 255 # 添加高斯噪声 cv2.randn(image, 235, 10) # 从opencv转PIL.Image ，带有透明度 return Image.fromarray(image).convert("RGBA")
创建晶体纹路背景图
def quasicrystal(height, width): image = Image.new("L", (width, height)) pixels = image.load() frequency = rnd.random() * 30 + 20 # frequency phase = rnd.random() * 2 * math.pi # phase rotation_count = rnd.randint(10, 20) # of rotations for kw in range(width): y = float(kw) / (width - 1) * 4 * math.pi - 2 * math.pi for kh in range(height): x = float(kh) / (height - 1) * 4 * math.pi - 2 * math.pi z = 0.0 for i in range(rotation_count): r = math.hypot(x, y) a = math.atan2(y, x) + i * math.pi * 2.0 / rotation_count z += math.cos(r * math.sin(a) * frequency + phase) c = int(255 - round(255 * z / rotation_count)) pixels[kw, kh] = c # grayscale return image.convert("RGBA")
通过图片创建背景
def image(height, width, image_dir): images = os.listdir(image_dir) if len(images) > 0: pic = Image.open( os.path.join(image_dir, images[rnd.randint(0, len(images) - 1)]) ) # 不失真resize if pic.size[0] < width: pic = pic.resize( [width, int(pic.size[1] * (width / pic.size[0]))], Image.ANTIALIAS ) if pic.size[1] < height: pic = pic.resize( [int(pic.size[0] * (height / pic.size[1])), height], Image.ANTIALIAS ) if pic.size[0] == width: x = 0 else: x = rnd.randint(0, pic.size[0] - width) if pic.size[1] == height: y = 0 else: y = rnd.randint(0, pic.size[1] - height) return pic.crop((x, y, x + width, y + height)) else: raise Exception("No images where found in the images folder!")
