// Copyright 2018 The MediaPipe Authors.
//
// 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.

syntax = "proto2";

package mediapipe;

import "mediapipe/framework/formats/annotation/rasterization.proto";

option cc_enable_arenas = true;

// A way to identify a part of an image. A locus does not need to correspond to
// a subset of pixels -- e.g. for a local descriptor we might define a locus in
// terms of its location and scale, even if the support of the descriptor is the
// entire image (with location-dependent weighting).
message Locus {
  // Types of image loci on the granularity of the annotation.
  enum LocusType {
    // The whole image, without localization.
    GLOBAL = 1;

    // The locus refers to a specified bounding box.
    // Requires bounding_box below.
    BOUNDING_BOX = 2;

    // The locus refers to specified regions in the image.
    // Requires region below.
    REGION = 3;

    // This locus refers to groups of loci. Requires component_locus below.
    VIDEO_TUBE = 4;
  }
  optional LocusType locus_type = 1;

  // A unique identifier for the locus. It is meaningless to compare the
  // locus_ids in different images. The client should not also assume that
  // applying the same processing to the same image multiple times will produce
  // the same locus_id.
  optional fixed64 locus_id = 2;
  optional fixed64 locus_id_seed = 6;

  // "Concatenatable" loci have the property that they appear in the same number
  // and order for all images, so their corresponding features can be
  // concatenated. Examples of concatenatable loci include global loci, those
  // corresponding to fixed bounding boxes, or a single most salient
  // region. Loci produced by segmentation with a variable number of segments,
  // on the other hand, are not concatenatable. This flag is true by default.
  optional bool concatenatable = 5 [default = true];

  // Required if locus_type = BOUNDING_BOX, Specifies a bounding box for the
  // label
  optional BoundingBox bounding_box = 3;

  // Specifies a timestamp if this locus appears in a video.
  // timestamp is specified in mSec from start of the video and refers to the
  // begining of the locus.
  optional int32 timestamp = 7 [default = -1];

  // Required if locus_type = REGION, Specifies a region using a scanline
  // encoding
  optional Rasterization region = 4;

  // Required if locus_type = VIDEO_TUBE. Specifies the component loci of the
  // tube.
  repeated Locus component_locus = 8;
}

// A representation of a bounding box.
message BoundingBox {
  optional int32 left_x = 1;
  optional int32 upper_y = 2;
  optional int32 right_x = 3;
  optional int32 lower_y = 4;
}
