照片尺寸转换

image_convert.py

# pip install opencv-python
import cv2


class ImageSize:
    def __init__(self):
        # 小一寸
        self._lt_one_inch_w = 260
        self._lt_one_inch_h = 390
        self._lt_one_ratio = self._lt_one_inch_w / self._lt_one_inch_h

        # 一寸
        self._one_inch_w = 295
        self._one_inch_h = 413
        self._one_ratio = self._one_inch_w / self._one_inch_h

        # 小二寸
        self._lt_two_inch_w = 390
        self._lt_two_inch_h = 567
        self._lt_two_ratio = self._lt_two_inch_w / self._lt_two_inch_h

        # 二寸
        self._two_inch_w = 413
        self._two_inch_h = 626
        self._two_ratio = self._two_inch_w / self._two_inch_h

        # 五寸
        self._five_inch_w = 840
        self._five_inch_h = 1200
        self._five_ratio = self._five_inch_w / self._five_inch_h

        # 六寸
        self._six_inch_w = 960
        self._six_inch_h = 1440
        self._six_ratio = self._six_inch_w / self._six_inch_h

        # 七寸
        self._seven_inch_w = 1680
        self._seven_inch_h = 1200
        self._seven_ratio = self._seven_inch_w / self._seven_inch_h

        # ID card
        self._id_inch_w = 358
        self._id_inch_h = 441
        self._id_ratio = self._id_inch_w / self._id_inch_h

    def lt_one_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._lt_one_ratio:
            ratio_img = self.crop_l_r(img, self._lt_one_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._lt_one_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._lt_one_inch_w, self._lt_one_inch_h))
        return resize_img

    def one_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._one_ratio:
            ratio_img = self.crop_l_r(img, self._one_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._one_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._one_inch_w, self._one_inch_h))
        return resize_img

    def lt_two_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._lt_two_ratio:
            ratio_img = self.crop_l_r(img, self._lt_two_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._lt_two_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._lt_two_inch_w, self._lt_two_inch_h))
        return resize_img

    def two_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._two_ratio:
            ratio_img = self.crop_l_r(img, self._two_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._two_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._two_inch_w, self._two_inch_h))
        return resize_img

    def five_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._five_ratio:
            ratio_img = self.crop_l_r(img, self._five_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._five_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._five_inch_w, self._five_inch_h))
        return resize_img

    def six_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._six_ratio:
            ratio_img = self.crop_l_r(img, self._six_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._six_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._six_inch_w, self._six_inch_h))
        return resize_img

    def seven_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._seven_ratio:
            ratio_img = self.crop_l_r(img, self._seven_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._seven_ratio, h, w)

        resize_img = cv2.resize(ratio_img,
                                (self._seven_inch_w, self._seven_inch_h))
        return resize_img

    def id_inch(self, img):
        img = img
        h, w = img.shape[:2]
        img_ratio = w / h

        if img_ratio >= self._id_ratio:
            ratio_img = self.crop_l_r(img, self._id_ratio, h, w)
        else:
            ratio_img = self.crop_d(img, self._id_ratio, h, w)

        resize_img = cv2.resize(ratio_img, (self._id_inch_w, self._id_inch_h))
        return resize_img

    def crop_l_r(self, img, ratio, h, w):
        """
		左右裁剪
		图片大小比例 > ratio
		"""
        crop_w = int(ratio * h)
        # 将w左右裁剪成这个crop_w的大小
        hide_w = (w - crop_w) // 2
        return_img = img[:, hide_w:w - hide_w]
        return return_img

    def crop_d(self, img, ratio, h, w):
        """
		图片下裁剪
		图片的大小比例 < ratio
		"""
        crop_h = int(w / ratio)
        hide_h = h - crop_h
        return_img = img[:h - hide_h, :]
        return return_img


if __name__ == "__main__":
    image_path = "demo.jpg"
    img = cv2.imread(image_path)
    imagesize = ImageSize()
    resize_img = imagesize.two_inch(img)
    cv2.imwrite('resize.jpg', resize_img)