Prototype of TFLite model metadata.

PiperOrigin-RevId: 263053990

tensorflow/lite/schema/BUILD

@@ -79,6 +79,12 @@ flatbuffer_cc_library(
     out_prefix = "reflection/",
 )
 
+# Generic schema for model metadata.
+flatbuffer_cc_library(
+    name = "metadata_schema_fbs",
+    srcs = ["metadata_schema.fbs"],
+)
+
 # Schema test to make sure we don't introduce backward incompatible changes
 # to schemas.
 cc_test(

tensorflow/lite/schema/metadata_schema.fbs

@@ -0,0 +1,160 @@
+// Copyright 2019 The TensorFlow Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+namespace tflite;
+
+// WARNING: This file contains experimental interface and is subject to change.
+
+// This corresponds to the version.
+file_identifier "TFLM";
+// File extension of any written files.
+file_extension "tflitemeta";
+
+enum AssociatedFileType : byte {
+  UNKNOWN = 0,
+  // Files such as readme.txt
+  DESCRIPTIONS = 1,
+  // Contains class labels used in classification. For example, the label files
+  // in image classification.
+  LABELS = 2,
+  // The vocab files used in NLP.
+  VOCABULARY = 3,
+  // Files that translate between languages, for example, the language resource
+  // file in Android.
+  LOCALIZATION = 4,
+}
+
+table AssociatedFile {
+  // Name of this file.
+  name:string;
+
+  // A description of what the file is.
+  description:string;
+
+  // Type of the associated file. There may be special pre/post processing for
+  // some types. For example in image classification, a label file of the output
+  // will be used to convert object index into string.
+  type:AssociatedFileType;
+}
+
+// The type of content that a tensor may represent.
+enum ContentType : byte {
+  UNKNOWN = 0,
+  IMAGE = 1,
+  VIDEO = 2,
+  TEXT = 3,
+  AUDIO = 4,
+  FEATURE = 5,
+}
+
+// The type of color space of an image.
+enum ColorSpaceType : byte {
+  UNKNOWN = 0,
+  RGB = 1,
+  BGR = 2,
+  YUV = 3,
+  HSV = 4,
+  GRAYSCALE = 5,
+}
+
+table ImageSize {
+  width:uint;
+  height:uint;
+}
+
+table ImageProperties {
+  // The color space of the image.
+  color_space:ColorSpaceType;
+
+  // Indicates the default value of image width and height if the tensor shape
+  // is dynamic. For fixed-size tensor, this size will be consistent with the
+  // expected size.
+  default_size:ImageSize;
+}
+
+// Detailed information of an input or output tensor.
+table TensorMetadata {
+  // Name of the tensor.
+  name:string;
+
+  // A description of the tensor.
+  description:string;
+
+  // The type of content that this tensor represents.
+  content_type:ContentType;
+
+  // Values are normailzed per-channelly by (x - mean) / std.
+  // If there is only one value in mean and std, we'll propogate the value to
+  // all channels.
+  // Mean of the possible values used in normalization.
+  mean:[float];
+
+  // Standard dev. of the possible values used in normalization.
+  std:[float];
+
+  // Properties that define an image. The section is used when the Content Type
+  // is specified as image.
+  image_properties:ImageProperties;
+
+  // A list of associated files of this tensor.
+  associated_files:[AssociatedFile];
+}
+
+table SubGraphMetadata {
+  // Name of the subgraph.
+  name:string;
+
+  // A description explains details about what the subgraph does.
+  description:string;
+
+  // Metadata of all input tensors used in this subgraph.
+  input_tensor_metadata:[TensorMetadata];
+
+  // Metadata of all output tensors used in this subgraph.
+  output_tensor_metadata:[TensorMetadata];
+
+  // A list of associated files of this subgraph.
+  associated_files:[AssociatedFile];
+}
+
+table ModelMetadata {
+  // Name of the model.
+  name:string;
+
+  // This is duplicated from the Model description in schema.
+  // description:string;
+
+  // Version of the model that specified by model creators.
+  version:string;
+
+  // Noted that, the minimum required TFLite runtime version that the model is
+  // compatible with, has already been added as a metadata entry in tflite
+  // schema. We'll decide later if we want to move it here, and keep it with
+  // other metadata entries.
+
+  // Metadata of all the subgraphs of the model. The 0th is assumed to be the
+  // main subgraph.
+  subgraph_metadata:[SubGraphMetadata];
+
+  // The person who creates this model.
+  author:string;
+
+  // Licenses that may apply to this model.
+  license:string;
+
+  // A list of associated files of this model.
+  associated_files:[AssociatedFile];
+}
+
+root_type ModelMetadata;