almost all of backend migrated; restoration next

invokeai/backend/image_util/util.py

@@ -0,0 +1,70 @@
+from math import sqrt, floor, ceil
+from PIL import Image
+
+class InitImageResizer():
+    """Simple class to create resized copies of an Image while preserving the aspect ratio."""
+    def __init__(self,Image):
+        self.image = Image
+
+    def resize(self,width=None,height=None) -> Image:
+        """
+        Return a copy of the image resized to fit within
+        a box width x height. The aspect ratio is
+        maintained. If neither width nor height are provided,
+        then returns a copy of the original image. If one or the other is
+        provided, then the other will be calculated from the
+        aspect ratio.
+
+        Everything is floored to the nearest multiple of 64 so
+        that it can be passed to img2img()
+        """
+        im    = self.image
+
+        ar = im.width/float(im.height)
+
+        # Infer missing values from aspect ratio
+        if not(width or height): # both missing
+            width  = im.width
+            height = im.height
+        elif not height:           # height missing
+            height = int(width/ar)
+        elif not width:            # width missing
+            width  = int(height*ar)
+
+        w_scale = width/im.width
+        h_scale = height/im.height
+        scale = min(w_scale,h_scale)
+        (rw,rh) = (int(scale*im.width),int(scale*im.height))
+
+        #round everything to multiples of 64
+        width,height,rw,rh = map(
+            lambda x: x-x%64, (width,height,rw,rh)
+        )
+
+        # no resize necessary, but return a copy
+        if im.width == width and im.height == height:
+            return im.copy()
+
+        # otherwise resize the original image so that it fits inside the bounding box
+        resized_image = self.image.resize((rw,rh),resample=Image.Resampling.LANCZOS)
+        return resized_image
+
+def make_grid(image_list, rows=None, cols=None):
+    image_cnt = len(image_list)
+    if None in (rows, cols):
+        rows = floor(sqrt(image_cnt))  # try to make it square
+        cols = ceil(image_cnt / rows)
+    width = image_list[0].width
+    height = image_list[0].height
+
+    grid_img = Image.new('RGB', (width * cols, height * rows))
+    i = 0
+    for r in range(0, rows):
+        for c in range(0, cols):
+            if i >= len(image_list):
+                break
+            grid_img.paste(image_list[i], (c * width, r * height))
+            i = i + 1
+
+    return grid_img
+