import PIL from PIL import Image,ImageOps def pad_image(image, target_size): """ :param image: input image :param target_size: a tuple (num,num) :return: new image """ iw, ih = image.size # 原始图像的尺寸 w, h = target_size # 目标图像的尺寸 scale = min(w / iw, h / ih) # 转换的最小比例 # 保证长或宽,至少一个符合目标图像的尺寸 0.5保证四舍五入 nw = int(iw * scale+0.5) nh = int(ih * scale+0.5) w += 128 h += 128 image = image.resize((nw, nh), PIL.Image.BICUBIC) # 更改图像尺寸,双立法插值效果很好 #image.show() new_image = PIL.Image.new('RGB', (w, h), (0, 0, 0)) # 生成黑色图像 # // 为整数除法,计算图像的位置 new_image.paste(image, ((w - nw) // 2, (h - nh) // 2)) # 将图像填充为中间图像,两侧为黑色的样式 return new_image def resize_image(image, target_size): width, height = image.size aspect_ratio = width / height if aspect_ratio > 1: # 宽度大于高度,以宽度为基准进行 resize new_width = target_size[0] new_height = int(new_width / aspect_ratio) else: # 高度大于宽度,以高度为基准进行 resize new_height = target_size[1] new_width = int(new_height * aspect_ratio) image = image.resize((new_width, new_height)) width_diff = target_size[0] - image.size[0] height_diff = target_size[1] - image.size[1] left_padding = 0 top_padding = 0 right_padding = width_diff - left_padding bottom_padding = height_diff - top_padding padded_image = ImageOps.expand(image, border=(left_padding, top_padding, right_padding, bottom_padding), fill=0) return padded_image