preprocessor.proto

syntax = "proto2";

package object_detection.protos;

// Message for defining a preprocessing operation on input data.
// See: //object_detection/core/preprocessor.py
message PreprocessingStep {
  oneof preprocessing_step {
    NormalizeImage normalize_image = 1;
    RandomHorizontalFlip random_horizontal_flip = 2;
    RandomPixelValueScale random_pixel_value_scale = 3;
    RandomImageScale random_image_scale = 4;
    RandomRGBtoGray random_rgb_to_gray = 5;
    RandomAdjustBrightness random_adjust_brightness = 6;
    RandomAdjustContrast random_adjust_contrast = 7;
    RandomAdjustHue random_adjust_hue = 8;
    RandomAdjustSaturation random_adjust_saturation = 9;
    RandomDistortColor random_distort_color = 10;
    RandomJitterBoxes random_jitter_boxes = 11;
    RandomCropImage random_crop_image = 12;
    RandomPadImage random_pad_image = 13;
    RandomCropPadImage random_crop_pad_image = 14;
    RandomCropToAspectRatio random_crop_to_aspect_ratio = 15;
    RandomBlackPatches random_black_patches = 16;
    RandomResizeMethod random_resize_method = 17;
    ScaleBoxesToPixelCoordinates scale_boxes_to_pixel_coordinates = 18;
    ResizeImage resize_image = 19;
    SubtractChannelMean subtract_channel_mean = 20;
    SSDRandomCrop ssd_random_crop = 21;
    SSDRandomCropPad ssd_random_crop_pad = 22;
    SSDRandomCropFixedAspectRatio ssd_random_crop_fixed_aspect_ratio = 23;
  }
}

// Normalizes pixel values in an image.
// For every channel in the image, moves the pixel values from the range
// [original_minval, original_maxval] to [target_minval, target_maxval].
message NormalizeImage {
  optional float original_minval = 1;
  optional float original_maxval = 2;
  optional float target_minval = 3 [default=0];
  optional float target_maxval = 4 [default=1];
}

// Randomly horizontally mirrors the image and detections 50% of the time.
message RandomHorizontalFlip {
}

// Randomly scales the values of all pixels in the image by some constant value
// between [minval, maxval], then clip the value to a range between [0, 1.0].
message RandomPixelValueScale {
  optional float minval = 1 [default=0.9];
  optional float maxval = 2 [default=1.1];
}

// Randomly enlarges or shrinks image (keeping aspect ratio).
message RandomImageScale {
  optional float min_scale_ratio = 1 [default=0.5];
  optional float max_scale_ratio = 2 [default=2.0];
}

// Randomly convert entire image to grey scale.
message RandomRGBtoGray {
  optional float probability = 1 [default=0.1];
}

// Randomly changes image brightness by up to max_delta. Image outputs will be
// saturated between 0 and 1.
message RandomAdjustBrightness {
  optional float max_delta=1 [default=0.2];
}

// Randomly scales contract by a value between [min_delta, max_delta].
message RandomAdjustContrast {
  optional float min_delta = 1 [default=0.8];
  optional float max_delta = 2 [default=1.25];
}

// Randomly alters hue by a value of up to max_delta.
message RandomAdjustHue {
  optional float max_delta = 1 [default=0.02];
}

// Randomly changes saturation by a value between [min_delta, max_delta].
message RandomAdjustSaturation {
  optional float min_delta = 1 [default=0.8];
  optional float max_delta = 2 [default=1.25];
}

// Performs a random color distortion. color_orderings should either be 0 or 1.
message RandomDistortColor {
  optional int32 color_ordering = 1;
}

// Randomly jitters corners of boxes in the image determined by ratio.
// ie. If a box is [100, 200] and ratio is 0.02, the corners can move by [1, 4].
message RandomJitterBoxes {
  optional float ratio = 1 [default=0.05];
}

// Randomly crops the image and bounding boxes.
message RandomCropImage {
  // Cropped image must cover at least one box by this fraction.
  optional float min_object_covered = 1 [default=1.0];

  // Aspect ratio bounds of cropped image.
  optional float min_aspect_ratio = 2 [default=0.75];
  optional float max_aspect_ratio = 3 [default=1.33];

  // Allowed area ratio of cropped image to original image.
  optional float min_area = 4 [default=0.1];
  optional float max_area = 5 [default=1.0];

  // Minimum overlap threshold of cropped boxes to keep in new image. If the
  // ratio between a cropped bounding box and the original is less than this
  // value, it is removed from the new image.
  optional float overlap_thresh = 6 [default=0.3];

  // Probability of keeping the original image.
  optional float random_coef = 7 [default=0.0];
}

// Randomly adds padding to the image.
message RandomPadImage {
  // Minimum dimensions for padded image. If unset, will use original image
  // dimension as a lower bound.
  optional float min_image_height = 1;
  optional float min_image_width = 2;

  // Maximum dimensions for padded image. If unset, will use double the original
  // image dimension as a lower bound.
  optional float max_image_height = 3;
  optional float max_image_width = 4;

  // Color of the padding. If unset, will pad using average color of the input
  // image.
  repeated float pad_color = 5;
}

// Randomly crops an image followed by a random pad.
message RandomCropPadImage {
  // Cropping operation must cover at least one box by this fraction.
  optional float min_object_covered = 1 [default=1.0];

  // Aspect ratio bounds of image after cropping operation.
  optional float min_aspect_ratio = 2 [default=0.75];
  optional float max_aspect_ratio = 3 [default=1.33];

  // Allowed area ratio of image after cropping operation.
  optional float min_area = 4 [default=0.1];
  optional float max_area = 5 [default=1.0];

  // Minimum overlap threshold of cropped boxes to keep in new image. If the
  // ratio between a cropped bounding box and the original is less than this
  // value, it is removed from the new image.
  optional float overlap_thresh = 6 [default=0.3];

  // Probability of keeping the original image during the crop operation.
  optional float random_coef = 7 [default=0.0];

  // Maximum dimensions for padded image. If unset, will use double the original
  // image dimension as a lower bound. Both of the following fields should be
  // length 2.
  repeated float min_padded_size_ratio = 8;
  repeated float max_padded_size_ratio = 9;

  // Color of the padding. If unset, will pad using average color of the input
  // image.
  repeated float pad_color = 10;
}

// Randomly crops an iamge to a given aspect ratio.
message RandomCropToAspectRatio {
  // Aspect ratio.
  optional float aspect_ratio = 1 [default=1.0];

  // Minimum overlap threshold of cropped boxes to keep in new image. If the
  // ratio between a cropped bounding box and the original is less than this
  // value, it is removed from the new image.
  optional float overlap_thresh = 2 [default=0.3];
}

// Randomly adds black square patches to an image.
message RandomBlackPatches {
  // The maximum number of black patches to add.
  optional int32 max_black_patches = 1 [default=10];

  // The probability of a black patch being added to an image.
  optional float probability = 2 [default=0.5];

  // Ratio between the dimension of the black patch to the minimum dimension of
  // the image (patch_width = patch_height = min(image_height, image_width)).
  optional float size_to_image_ratio = 3 [default=0.1];
}

// Randomly resizes the image up to [target_height, target_width].
message RandomResizeMethod {
  optional float target_height = 1;
  optional float target_width = 2;
}

// Scales boxes from normalized coordinates to pixel coordinates.
message ScaleBoxesToPixelCoordinates {
}

// Resizes images to [new_height, new_width].
message ResizeImage {
  optional int32 new_height = 1;
  optional int32 new_width = 2;
  enum Method {
    AREA=1;
    BICUBIC=2;
    BILINEAR=3;
    NEAREST_NEIGHBOR=4;
  }
  optional Method method = 3 [default=BILINEAR];
}

// Normalizes an image by subtracting a mean from each channel.
message SubtractChannelMean {
  // The mean to subtract from each channel. Should be of same dimension of
  // channels in the input image.
  repeated float means = 1;
}

message SSDRandomCropOperation {
  // Cropped image must cover at least this fraction of one original bounding
  // box.
  optional float min_object_covered = 1;

  // The aspect ratio of the cropped image must be within the range of
  // [min_aspect_ratio, max_aspect_ratio].
  optional float min_aspect_ratio = 2;
  optional float max_aspect_ratio = 3;

  // The area of the cropped image must be within the range of
  // [min_area, max_area].
  optional float min_area = 4;
  optional float max_area = 5;

  // Cropped box area ratio must be above this threhold to be kept.
  optional float overlap_thresh = 6;

  // Probability a crop operation is skipped.
  optional float random_coef = 7;
}

// Randomly crops a image according to:
//     Liu et al., SSD: Single shot multibox detector.
// This preprocessing step defines multiple SSDRandomCropOperations. Only one
// operation (chosen at random) is actually performed on an image.
message SSDRandomCrop {
  repeated SSDRandomCropOperation operations = 1;
}

message SSDRandomCropPadOperation {
  // Cropped image must cover at least this fraction of one original bounding
  // box.
  optional float min_object_covered = 1;

  // The aspect ratio of the cropped image must be within the range of
  // [min_aspect_ratio, max_aspect_ratio].
  optional float min_aspect_ratio = 2;
  optional float max_aspect_ratio = 3;

  // The area of the cropped image must be within the range of
  // [min_area, max_area].
  optional float min_area = 4;
  optional float max_area = 5;

  // Cropped box area ratio must be above this threhold to be kept.
  optional float overlap_thresh = 6;

  // Probability a crop operation is skipped.
  optional float random_coef = 7;

  // Min ratio of padded image height and width to the input image's height and
  // width. Two entries per operation.
  repeated float min_padded_size_ratio = 8;

  // Max ratio of padded image height and width to the input image's height and
  // width. Two entries per operation.
  repeated float max_padded_size_ratio = 9;

  // Padding color.
  optional float pad_color_r = 10;
  optional float pad_color_g = 11;
  optional float pad_color_b = 12;
}

// Randomly crops and pads an image according to:
//     Liu et al., SSD: Single shot multibox detector.
// This preprocessing step defines multiple SSDRandomCropPadOperations. Only one
// operation (chosen at random) is actually performed on an image.
message SSDRandomCropPad {
  repeated SSDRandomCropPadOperation operations = 1;
}

message SSDRandomCropFixedAspectRatioOperation {
  // Cropped image must cover at least this fraction of one original bounding
  // box.
  optional float min_object_covered = 1;

  // The area of the cropped image must be within the range of
  // [min_area, max_area].
  optional float min_area = 4;
  optional float max_area = 5;

  // Cropped box area ratio must be above this threhold to be kept.
  optional float overlap_thresh = 6;

  // Probability a crop operation is skipped.
  optional float random_coef = 7;
}

// Randomly crops a image to a fixed aspect ratio according to:
//     Liu et al., SSD: Single shot multibox detector.
// Multiple SSDRandomCropFixedAspectRatioOperations are defined by this
// preprocessing step. Only one operation (chosen at random) is actually
// performed on an image.
message SSDRandomCropFixedAspectRatio {
  repeated SSDRandomCropFixedAspectRatioOperation operations = 1;

  // Aspect ratio to crop to. This value is used for all crop operations.
  optional float aspect_ratio = 2 [default=1.0];
}