Add 2 nodes, remove alpha + convert image to grayscale

remove_transparency.py

@@ -0,0 +1,47 @@
+import torch
+
+class RemoveTransparency:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "image": ("IMAGE",),
+                "recover_background": ("BOOLEAN", {"default": False}),
+                "background_color": (["black", "white", "greenscreen"], {"default": "black"}),
+            },
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "process_transparency"
+
+    CATEGORY = "Bjornulf"
+
+    def process_transparency(self, image, recover_background, background_color):
+        # Check if the image has an alpha channel
+        if image.shape[3] == 4:
+            rgb = image[:, :, :, :3]
+            alpha = image[:, :, :, 3:4]
+            
+            if recover_background:
+                result = rgb
+            else:
+                # Create background color tensor
+                if background_color == "white":
+                    bg_color = torch.ones_like(rgb)
+                elif background_color == "greenscreen":
+                    bg_color = torch.zeros_like(rgb)
+                    bg_color[:, :, :, 1] = 1  # Set green channel to 1
+                else:  # black
+                    bg_color = torch.zeros_like(rgb)
+                
+                # Blend the image with the background color
+                result = rgb * alpha + bg_color * (1 - alpha)
+        else:
+            # If there's no alpha channel, return the original image
+            result = image
+
+        # Ensure the output is always 3 channels (RGB)
+        if result.shape[3] == 4:
+            result = result[:, :, :, :3]
+
+        return (result,)