tweak invocation name

invokeai/app/invocations/image.py

@@ -16,7 +16,7 @@ from invokeai.app.invocations.fields import (
     WithBoard,
     WithMetadata,
 )
-from invokeai.app.invocations.primitives import ImageOutput
+from invokeai.app.invocations.primitives import ImageOutput, StringOutput
 from invokeai.app.services.image_records.image_records_common import ImageCategory
 from invokeai.app.services.shared.invocation_context import InvocationContext
 from invokeai.backend.image_util.invisible_watermark import InvisibleWatermark
@@ -542,6 +542,25 @@ class ImageWatermarkInvocation(BaseInvocation, WithMetadata, WithBoard):
         return ImageOutput.build(image_dto)
 
 
+@invocation(
+    "retrieve_watermark",
+    title="Retrieve Invisible Watermark",
+    tags=["image", "watermark"],
+    category="image",
+    version="1.2.2",
+)
+class RetrieveWatermarkInvocation(BaseInvocation):
+    """Read an invisible watermark from an image"""
+
+    image: ImageField = InputField(description="The image to read the watermark from")
+    watermark_len: int = InputField(default=8, description="length of watermark, in characters")
+
+    def invoke(self, context: InvocationContext) -> StringOutput:
+        image = context.images.get_pil(self.image.image_name)
+        watermark_text = InvisibleWatermark.read_watermark(image, self.watermark_len * 8)
+        return StringOutput(value=watermark_text)
+
+
 @invocation(
     "mask_edge",
     title="Mask Edge",

invokeai/backend/image_util/invisible_watermark.py

@@ -6,7 +6,7 @@ configuration variable, that allows the watermarking to be supressed.
 
 import cv2
 import numpy as np
-from imwatermark import WatermarkEncoder
+from imwatermark import WatermarkDecoder, WatermarkEncoder
 from PIL import Image
 
 import invokeai.backend.util.logging as logger
@@ -28,3 +28,10 @@ class InvisibleWatermark:
         encoder.set_watermark("bytes", watermark_text.encode("utf-8"))
         bgr_encoded = encoder.encode(bgr, "dwtDct")
         return Image.fromarray(cv2.cvtColor(bgr_encoded, cv2.COLOR_BGR2RGB)).convert("RGBA")
+
+    @classmethod
+    def read_watermark(cls, image: Image.Image, length: int = 64) -> str:
+        bgr = cv2.cvtColor(np.array(image.convert("RGB")), cv2.COLOR_RGB2BGR)
+        decoder = WatermarkDecoder("bytes", length)
+        watermark = decoder.decode(bgr, "dwtDct")
+        return watermark.decode("utf-8")