⚡ Bolt: Optimize Discord PNG encoding

Avoid unnecessary PIL->Numpy conversion when sending PNGs to Discord, saving ~500ms for 4K images.
This is achieved by tracking if the image was resized and reusing the original numpy array if possible.

.jules/bolt.md

@@ -14,3 +14,9 @@
 - Naive conversion `np.clip(255. * tensor.cpu().numpy(), 0, 255).astype(np.uint8)` creates large intermediate float arrays on CPU.
 - Performing scaling, clamping, and casting on the tensor *before* moving to CPU (`(tensor * 255.0).clamp(0, 255).to(dtype=torch.uint8).cpu().numpy()`) is significantly faster and more memory efficient.
 **Action:** Always process tensors (scale/clamp/cast) before converting to numpy/CPU when preparing images for PIL/OpenCV.
+
+## 2026-01-14 - Avoid Redundant PIL to Numpy Conversion
+**Learning:**
+- Converting a large PIL Image back to a Numpy array (`np.array(img)`) is surprisingly slow (measured ~500ms for 4K image).
+- When the PIL Image wraps an existing Numpy array and hasn't been modified (e.g. resized), reusing the original Numpy array avoids this overhead completely.
+**Action:** Track modifications to PIL images (like resizing) and reuse the source Numpy array for OpenCV operations if no modifications occurred.

discord_image_node.py

@@ -432,6 +432,9 @@ class DiscordSendSaveImage:
             i = tensor_to_numpy_uint8(image)
             img = Image.fromarray(i)
             
+            # Track if resizing happened to optimize Discord encoding later
+            was_resized = False
+
             # Get original dimensions before any resizing
             orig_width, orig_height = img.size
             
@@ -452,11 +455,13 @@ class DiscordSendSaveImage:
                 if (new_width != orig_width or new_height != orig_height):
                     try:
                         img = img.resize((new_width, new_height), selected_resize_method)
+                        was_resized = True
                         print(f"Successfully resized using {resize_method} method")
                     except Exception as e:
                         print(f"Error during power of 2 resize: {e}")
                         # Fallback to BICUBIC if selected method fails
                         img = img.resize((new_width, new_height), Image.BICUBIC)
+                        was_resized = True
                         print("Fallback to BICUBIC resize method due to error")
             
             # Get dimensions - either original or resized
@@ -598,7 +603,12 @@ class DiscordSendSaveImage:
 
                         elif file_format == "png":
                             # Use CV2 for PNG (significantly faster)
-                            img_cv = np.array(img)
+                            # Optimization: If image wasn't resized, use the original numpy array 'i'
+                            # This avoids an expensive PIL->Numpy conversion/copy (~500ms for 4K images)
+                            if not was_resized:
+                                img_cv = i
+                            else:
+                                img_cv = np.array(img)
 
                             # Convert RGB (PIL) to BGR (OpenCV)
                             if len(img_cv.shape) == 3 and img_cv.shape[2] == 3: