support setting centre point of crop

Author: tykling

src/bma_client_lib/pillow_resize_and_crop.py

@@ -8,7 +8,7 @@
 from PIL import Image, ImageFile, ImageSequence
 
 
-def transform_image(original_img: Image.Image, crop_w: int, crop_h: int) -> list[Image.Image | ImageFile.ImageFile]:
+def transform_image(original_img: Image.Image, crop_w: int, crop_h: int, center_point: tuple[int, int] = (0.5,0.5)) -> list[Image.Image | ImageFile.ImageFile]:
     """Resizes and crops the image to the specified crop_w and crop_h if necessary.
 
     Works with multi frame gif and webp images.
@@ -22,6 +22,7 @@ def transform_image(original_img: Image.Image, crop_w: int, crop_h: int) -> list
       Instance of an Image or list of frames which they are instances of an Image individually
     """
     img_w, img_h = (original_img.size[0], original_img.size[1])
+    # sequence?
     n_frames = getattr(original_img, "n_frames", 1)
 
     def transform_frame(frame: Image.Image) -> Image.Image | ImageFile.ImageFile:
@@ -52,9 +53,9 @@ def transform_frame(frame: Image.Image) -> Image.Image | ImageFile.ImageFile:
             new_w = crop_w if h_diff > w_diff else floor(crop_h * img_w / img_h)
             new_h = crop_h if h_diff < w_diff else floor(crop_w * img_h / img_w)
 
-        left = (new_w - crop_w) // 2
+        left = (new_w - crop_w) * center_point[0]
         right = left + crop_w
-        top = (new_h - crop_h) // 2
+        top = (new_h - crop_h) * center_point[1]
         bottom = top + crop_h
 
         return frame.resize((new_w, new_h), resample=Image.Resampling.LANCZOS).crop((left, top, right, bottom))