utils.py 文件源码

def preprocess_image_scale(image_path, img_size=None):
    '''
    Preprocess the image scaling it so that its larger size is max_size.
    This function preserves aspect ratio.
    '''
    img = load_img(image_path)
    if img_size:
        scale = float(img_size) / max(img.size)
        new_size = (int(np.ceil(scale * img.size[0])), int(np.ceil(scale * img.size[1])))
        img = img.resize(new_size, resample=Image.BILINEAR)
    img = img_to_array(img)
    img = np.expand_dims(img, axis=0)
    img = vgg16.preprocess_input(img)
    return img


# util function to convert a tensor into a valid image