upstream MaskPreview from ComfyUI_essentials (#7719)

comfy_extras/nodes_mask.py

@@ -3,7 +3,10 @@ import scipy.ndimage
 import torch
 import comfy.utils
 import node_helpers
+import folder_paths
+import random
 
+import nodes
 from nodes import MAX_RESOLUTION
 
 def composite(destination, source, x, y, mask = None, multiplier = 8, resize_source = False):
@@ -362,6 +365,30 @@ class ThresholdMask:
         mask = (mask > value).float()
         return (mask,)
 
+# Mask Preview - original implement from
+# https://github.com/cubiq/ComfyUI_essentials/blob/9d9f4bedfc9f0321c19faf71855e228c93bd0dc9/mask.py#L81
+# upstream requested in https://github.com/Kosinkadink/rfcs/blob/main/rfcs/0000-corenodes.md#preview-nodes
+class MaskPreview(nodes.SaveImage):
+    def __init__(self):
+        self.output_dir = folder_paths.get_temp_directory()
+        self.type = "temp"
+        self.prefix_append = "_temp_" + ''.join(random.choice("abcdefghijklmnopqrstupvxyz") for x in range(5))
+        self.compress_level = 4
+
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {"mask": ("MASK",), },
+            "hidden": {"prompt": "PROMPT", "extra_pnginfo": "EXTRA_PNGINFO"},
+        }
+
+    FUNCTION = "execute"
+    CATEGORY = "mask"
+
+    def execute(self, mask, filename_prefix="ComfyUI", prompt=None, extra_pnginfo=None):
+        preview = mask.reshape((-1, 1, mask.shape[-2], mask.shape[-1])).movedim(1, -1).expand(-1, -1, -1, 3)
+        return self.save_images(preview, filename_prefix, prompt, extra_pnginfo)
+
 
 NODE_CLASS_MAPPINGS = {
     "LatentCompositeMasked": LatentCompositeMasked,
@@ -376,6 +403,7 @@ NODE_CLASS_MAPPINGS = {
     "FeatherMask": FeatherMask,
     "GrowMask": GrowMask,
     "ThresholdMask": ThresholdMask,
+    "MaskPreview": MaskPreview
 }
 
 NODE_DISPLAY_NAME_MAPPINGS = {