Added property to get labels from iOS Image Segmenter

mediapipe/tasks/ios/core/sources/MPPTaskRunner.h

@@ -36,6 +36,12 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @interface MPPTaskRunner : NSObject
 
+/** 
+ * The canonicalized `CalculatorGraphConfig` of the underlying graph managed by the C++ task
+ * runner. 
+ */
+@property(nonatomic, readonly) const mediapipe::CalculatorGraphConfig &graphConfig;
+
 /**
  * Initializes a new `MPPTaskRunner` with the MediaPipe calculator configuration proto and an
  * optional C++ packets callback.

mediapipe/tasks/ios/core/sources/MPPTaskRunner.mm

@@ -33,6 +33,10 @@ using TaskRunnerCpp = ::mediapipe::tasks::core::TaskRunner;
 
 @implementation MPPTaskRunner
 
+- (const CalculatorGraphConfig &)graphConfig {
+  return _cppTaskRunner->GetGraphConfig();
+}
+
 - (instancetype)initWithCalculatorGraphConfig:(CalculatorGraphConfig)graphConfig
                               packetsCallback:(PacketsCallback)packetsCallback
                                         error:(NSError **)error {

mediapipe/tasks/ios/vision/image_segmenter/BUILD

@@ -51,6 +51,8 @@ objc_library(
         ":MPPImageSegmenterOptions",
         ":MPPImageSegmenterResult",
         "//mediapipe/tasks/cc/vision/image_segmenter:image_segmenter_graph",
+        "//mediapipe/tasks/cc/vision/image_segmenter/calculators:tensors_to_segmentation_calculator",
+        "//mediapipe/tasks/ios/common:MPPCommon",
         "//mediapipe/tasks/ios/common/utils:MPPCommonUtils",
         "//mediapipe/tasks/ios/common/utils:NSStringHelpers",
         "//mediapipe/tasks/ios/core:MPPTaskInfo",

mediapipe/tasks/ios/vision/image_segmenter/sources/MPPImageSegmenter.h

@@ -29,27 +29,31 @@ NS_SWIFT_NAME(ImageSegmenter)
 @interface MPPImageSegmenter : NSObject
 
 /**
- * Creates a new instance of `MPPImageSegmenter` from an absolute path to a TensorFlow Lite model
+ * Get the category label list of the `ImageSegmenter` can recognize. For CATEGORY_MASK type, the
- * file stored locally on the device and the default `MPPImageSegmenterOptions`.
+ * index in the category mask corresponds to the category in the label list. For CONFIDENCE_MASK
+ * type, the output mask list at index corresponds to the category in the label list. If there is no
+ * labelmap provided in the model file, empty array is returned.
+ */
+@property(nonatomic, readonly) NSArray<NSString *> *labels;
+
+/**
+ * Creates a new instance of `ImageSegmenter` from an absolute path to a TensorFlow Lite model
+ * file stored locally on the device and the default `ImageSegmenterOptions`.
  *
  * @param modelPath An absolute path to a TensorFlow Lite model file stored locally on the device.
- * @param error An optional error parameter populated when there is an error in initializing the
- * image segmenter.
  *
- * @return A new instance of `MPPImageSegmenter` with the given model path. `nil` if there is an
+ * @return A new instance of `ImageSegmenter` with the given model path. `nil` if there is an
  * error in initializing the image segmenter.
  */
 - (nullable instancetype)initWithModelPath:(NSString *)modelPath error:(NSError **)error;
 
 /**
- * Creates a new instance of `MPPImageSegmenter` from the given `MPPImageSegmenterOptions`.
+ * Creates a new instance of `ImageSegmenter` from the given `ImageSegmenterOptions`.
  *
- * @param options The options of type `MPPImageSegmenterOptions` to use for configuring the
+ * @param options The options of type `ImageSegmenterOptions` to use for configuring the
- * `MPPImageSegmenter`.
+ * `ImageSegmenter`.
- * @param error An optional error parameter populated when there is an error in initializing the
- * image segmenter.
  *
- * @return A new instance of `MPPImageSegmenter` with the given options. `nil` if there is an error
+ * @return A new instance of `ImageSegmenter` with the given options. `nil` if there is an error
  * in initializing the image segmenter.
  */
 - (nullable instancetype)initWithOptions:(MPPImageSegmenterOptions *)options
@@ -57,23 +61,20 @@ NS_SWIFT_NAME(ImageSegmenter)
 
 /**
  * Performs segmentation on the provided MPPImage using the whole image as region of interest.
- * Rotation will be applied according to the `orientation` property of the provided `MPPImage`. Only
+ * Rotation will be applied according to the `orientation` property of the provided `MPImage`. Only
- * use this method when the `MPPImageSegmenter` is created with `MPPRunningModeImage`.
+ * use this method when the `ImageSegmenter` is created with running mode, `image`.
  *
- * This method supports RGBA images. If your `MPPImage` has a source type of
+ * This method supports RGBA images. If your `MPImage` has a source type of `pixelBuffer` or
- * `MPPImageSourceTypePixelBuffer` or `MPPImageSourceTypeSampleBuffer`, the underlying pixel buffer
+ * `sampleBuffer`, the underlying pixel buffer must have one of the following pixel format types:
- * must have one of the following pixel format types:
  * 1. kCVPixelFormatType_32BGRA
  * 2. kCVPixelFormatType_32RGBA
  *
- * If your `MPPImage` has a source type of `MPPImageSourceTypeImage` ensure that the color space is
+ * If your `MPImage` has a source type of `.image` ensure that the color space is RGB with an Alpha
- * RGB with an Alpha channel.
+ * channel.
  *
- * @param image The `MPPImage` on which segmentation is to be performed.
+ * @param image The `MPImage` on which segmentation is to be performed.
- * @param error An optional error parameter populated when there is an error in performing
- * segmentation on the input image.
  *
- * @return An `MPPImageSegmenterResult` that contains the segmented masks.
+ * @return An `ImageSegmenterResult` that contains the segmented masks.
  */
 - (nullable MPPImageSegmenterResult *)segmentImage:(MPPImage *)image
                                              error:(NSError **)error NS_SWIFT_NAME(segment(image:));
@@ -83,22 +84,20 @@ NS_SWIFT_NAME(ImageSegmenter)
  * invokes the given completion handler block with the response. The method returns synchronously
  * once the completion handler returns.
  *
- * Rotation will be applied according to the `orientation` property of the provided
+ * Rotation will be applied according to the `orientation` property of the provided `MPImage`. Only
- * `MPPImage`. Only use this method when the `MPPImageSegmenter` is created with
+ * use this method when the `ImageSegmenter` is created with running mode, `image`.
- * `MPPRunningModeImage`.
  *
- * This method supports RGBA images. If your `MPPImage` has a source type of
+ * This method supports RGBA images. If your `MPImage` has a source type of `pixelBuffer` or
- * `MPPImageSourceTypePixelBuffer` or `MPPImageSourceTypeSampleBuffer`, the underlying pixel buffer
+ * `sampleBuffer`, the underlying pixel buffer must have one of the following pixel format types:
- * must have one of the following pixel format types:
  * 1. kCVPixelFormatType_32BGRA
  * 2. kCVPixelFormatType_32RGBA
  *
- * If your `MPPImage` has a source type of `MPPImageSourceTypeImage` ensure that the color space is
+ * If your `MPImage` has a source type of `image` ensure that the color space is RGB with an Alpha
- * RGB with an Alpha channel.
+ * channel.
  *
- * @param image The `MPPImage` on which segmentation is to be performed.
+ * @param image The `MPImage` on which segmentation is to be performed.
  * @param completionHandler A block to be invoked with the results of performing segmentation on the
- * image. The block takes two arguments, the optional `MPPImageSegmenterResult` that contains the
+ * image. The block takes two arguments, the optional `ImageSegmenterResult` that contains the
  * segmented masks if the segmentation was successful and an optional error populated upon failure.
  * The lifetime of the returned masks is only guaranteed for the duration of the block.
  */
@@ -108,28 +107,25 @@ NS_SWIFT_NAME(ImageSegmenter)
     NS_SWIFT_NAME(segment(image:completion:));
 
 /**
- * Performs segmentation on the provided video frame of type `MPPImage` using the whole image as
+ * Performs segmentation on the provided video frame of type `MPImage` using the whole image as
  * region of interest.
  *
- * Rotation will be applied according to the `orientation` property of the provided `MPPImage`. Only
+ * Rotation will be applied according to the `orientation` property of the provided `MPImage`. Only
- * use this method when the `MPPImageSegmenter` is created with `MPPRunningModeVideo`.
+ * use this method when the `ImageSegmenter` is created with `video`.
  *
- * This method supports RGBA images. If your `MPPImage` has a source type of
+ * This method supports RGBA images. If your `MPImage` has a source type of `pixelBuffer` or
- * `MPPImageSourceTypePixelBuffer` or `MPPImageSourceTypeSampleBuffer`, the underlying pixel buffer
+ * `sampleBuffer`, the underlying pixel buffer must have one of the following pixel format types:
- * must have one of the following pixel format types:
  * 1. kCVPixelFormatType_32BGRA
  * 2. kCVPixelFormatType_32RGBA
  *
- * If your `MPPImage` has a source type of `MPPImageSourceTypeImage` ensure that the color space is
+ * If your `MPImage` has a source type of `image` ensure that the color space is RGB with an Alpha
- * RGB with an Alpha channel.
+ * channel.
  *
- * @param image The `MPPImage` on which segmentation is to be performed.
+ * @param image The `MPImage` on which segmentation is to be performed.
  * @param timestampInMilliseconds The video frame's timestamp (in milliseconds). The input
  * timestamps must be monotonically increasing.
- * @param error An optional error parameter populated when there is an error in performing
- * segmentation on the input image.
  *
- * @return An `MPPImageSegmenterResult` that contains a the segmented masks.
+ * @return An `ImageSegmenterResult` that contains a the segmented masks.
  */
 - (nullable MPPImageSegmenterResult *)segmentVideoFrame:(MPPImage *)image
                                 timestampInMilliseconds:(NSInteger)timestampInMilliseconds
@@ -137,27 +133,26 @@ NS_SWIFT_NAME(ImageSegmenter)
     NS_SWIFT_NAME(segment(videoFrame:timestampInMilliseconds:));
 
 /**
- * Performs segmentation on the provided video frame of type `MPPImage` using the whole image as
+ * Performs segmentation on the provided video frame of type `MPImage` using the whole image as
  * region of interest invokes the given completion handler block with the response. The method
  * returns synchronously once the completion handler returns.
  *
- * Rotation will be applied according to the `orientation` property of the provided `MPPImage`. Only
+ * Rotation will be applied according to the `orientation` property of the provided `MPImage`. Only
- * use this method when the `MPPImageSegmenter` is created with `MPPRunningModeVideo`.
+ * use this method when the `ImageSegmenter` is created with running mode, `video`.
  *
- * This method supports RGBA images. If your `MPPImage` has a source type of
+ * This method supports RGBA images. If your `MPImage` has a source type of `pixelBuffer` or
- * `MPPImageSourceTypePixelBuffer` or `MPPImageSourceTypeSampleBuffer`, the underlying pixel buffer
+ * `sampleBuffer`, the underlying pixel buffer must have one of the following pixel format types:
- * must have one of the following pixel format types:
  * 1. kCVPixelFormatType_32BGRA
  * 2. kCVPixelFormatType_32RGBA
  *
- * If your `MPPImage` has a source type of `MPPImageSourceTypeImage` ensure that the color space is
+ * If your `MPImage` has a source type of `image` ensure that the color space is RGB with an Alpha
- * RGB with an Alpha channel.
+ * channel.
  *
- * @param image The `MPPImage` on which segmentation is to be performed.
+ * @param image The `MPImage` on which segmentation is to be performed.
  * @param timestampInMilliseconds The video frame's timestamp (in milliseconds). The input
  * timestamps must be monotonically increasing.
  * @param completionHandler A block to be invoked with the results of performing segmentation on the
- * image. The block takes two arguments, the optional `MPPImageSegmenterResult` that contains the
+ * image. The block takes two arguments, the optional `ImageSegmenterResult` that contains the
  * segmented masks if the segmentation was successful and an optional error only populated upon
  * failure. The lifetime of the returned masks is only guaranteed for the duration of the block.
  */
@@ -168,38 +163,36 @@ NS_SWIFT_NAME(ImageSegmenter)
     NS_SWIFT_NAME(segment(videoFrame:timestampInMilliseconds:completion:));
 
 /**
- * Sends live stream image data of type `MPPImage` to perform segmentation using the whole image as
+ * Sends live stream image data of type `MPImage` to perform segmentation using the whole image as
  *region of interest.
  *
- * Rotation will be applied according to the `orientation` property of the provided `MPPImage`. Only
+ * Rotation will be applied according to the `orientation` property of the provided `MPImage`. Only
- * use this method when the `MPPImageSegmenter` is created with`MPPRunningModeLiveStream`.
+ *use this method when the `ImageSegmenter` is created with running mode, `liveStream`.
  *
  * The object which needs to be continuously notified of the available results of image segmentation
- * must confirm to `MPPImageSegmenterLiveStreamDelegate` protocol and implement the
+ * must confirm to `ImageSegmenterLiveStreamDelegate` protocol and implement the
- *`imageSegmenter:didFinishSegmentationWithResult:timestampInMilliseconds:error:` delegate method.
+ * `imageSegmenter(_:didFinishSegmentationWithResult:timestampInMilliseconds:error:)` delegate
+ * method.
  *
  * It's required to provide a timestamp (in milliseconds) to indicate when the input image is sent
  * to the segmenter. The input timestamps must be monotonically increasing.
  *
- * This method supports RGBA images. If your `MPPImage` has a source type of
+ * This method supports RGBA images. If your `MPImage` has a source type of `pixelBuffer` or
- *`MPPImageSourceTypePixelBuffer` or `MPPImageSourceTypeSampleBuffer`, the underlying pixel buffer
+ *`sampleBuffer`, the underlying pixel buffer must have one of the following pixel format types:
- * must have one of the following pixel format types:
  * 1. kCVPixelFormatType_32BGRA
  * 2. kCVPixelFormatType_32RGBA
  *
- * If the input `MPPImage` has a source type of `MPPImageSourceTypeImage` ensure that the color
+ * If the input `MPImage` has a source type of `image` ensure that the color space is RGB with an
- * space is RGB with an Alpha channel.
+ * Alpha channel.
  *
  * If this method is used for classifying live camera frames using `AVFoundation`, ensure that you
  * request `AVCaptureVideoDataOutput` to output frames in `kCMPixelFormat_32RGBA` using its
  * `videoSettings` property.
  *
- * @param image A live stream image data of type `MPPImage` on which segmentation is to be
+ * @param image A live stream image data of type `MPImage` on which segmentation is to be
  * performed.
  * @param timestampInMilliseconds The timestamp (in milliseconds) which indicates when the input
  * image is sent to the segmenter. The input timestamps must be monotonically increasing.
- * @param error An optional error parameter populated when there is an error when sending the input
- * image to the graph.
  *
  * @return `YES` if the image was sent to the task successfully, otherwise `NO`.
  */

mediapipe/tasks/ios/vision/image_segmenter/sources/MPPImageSegmenter.mm

@@ -14,6 +14,7 @@
 
 #import "mediapipe/tasks/ios/vision/image_segmenter/sources/MPPImageSegmenter.h"
 
+#import "mediapipe/tasks/ios/common/sources/MPPCommon.h"
 #import "mediapipe/tasks/ios/common/utils/sources/MPPCommonUtils.h"
 #import "mediapipe/tasks/ios/common/utils/sources/NSString+Helpers.h"
 #import "mediapipe/tasks/ios/core/sources/MPPTaskInfo.h"
@@ -21,6 +22,8 @@
 #import "mediapipe/tasks/ios/vision/image_segmenter/utils/sources/MPPImageSegmenterOptions+Helpers.h"
 #import "mediapipe/tasks/ios/vision/image_segmenter/utils/sources/MPPImageSegmenterResult+Helpers.h"
 
+#include "mediapipe/tasks/cc/vision/image_segmenter/calculators/tensors_to_segmentation_calculator.pb.h"
+
 static constexpr int kMicrosecondsPerMillisecond = 1000;
 
 // Constants for the underlying MP Tasks Graph. See
@@ -48,7 +51,9 @@ static NSString *const kTaskName = @"imageSegmenter";
   }
 
 namespace {
+using ::mediapipe::CalculatorGraphConfig;
 using ::mediapipe::Timestamp;
+using ::mediapipe::tasks::TensorsToSegmentationCalculatorOptions;
 using ::mediapipe::tasks::core::PacketMap;
 using ::mediapipe::tasks::core::PacketsCallback;
 }  // anonymous namespace
@@ -125,10 +130,15 @@ using ::mediapipe::tasks::core::PacketsCallback;
                                                  imageInputStreamName:kImageInStreamName
                                               normRectInputStreamName:kNormRectStreamName
                                                                 error:error];
-
     if (!_visionTaskRunner) {
       return nil;
     }
+
+    _labels = [MPPImageSegmenter populateLabelsWithGraphConfig:_visionTaskRunner.graphConfig
+                                                         error:error];
+    if (!_labels) {
+      return nil;
+    }
   }
 
   return self;
@@ -197,6 +207,43 @@ using ::mediapipe::tasks::core::PacketsCallback;
 
 #pragma mark - Private
 
++ (NSArray<NSString *> *)populateLabelsWithGraphConfig:(const CalculatorGraphConfig &)graphConfig
+                                                 error:(NSError **)error {
+  bool found_tensor_to_segmentation_calculator = false;
+
+  NSMutableArray *labels = [NSMutableArray arrayWithCapacity:(NSUInteger)graphConfig.node_size()];
+  for (const auto &node : graphConfig.node()) {
+    if (node.calculator() == "mediapipe.tasks.TensorsToSegmentationCalculator") {
+      if (!found_tensor_to_segmentation_calculator) {
+        found_tensor_to_segmentation_calculator = true;
+      } else {
+        [MPPCommonUtils createCustomError:error
+                                 withCode:MPPTasksErrorCodeFailedPreconditionError
+                              description:@"The graph has more than one "
+                                          @"`mediapipe.tasks.TensorsToSegmentationCalculator`."];
+        return nil;
+      }
+      TensorsToSegmentationCalculatorOptions options =
+          node.options().GetExtension(TensorsToSegmentationCalculatorOptions::ext);
+      if (!options.label_items().empty()) {
+        for (int i = 0; i < options.label_items_size(); ++i) {
+          if (!options.label_items().contains(i)) {
+            [MPPCommonUtils
+                createCustomError:error
+                         withCode:MPPTasksErrorCodeFailedPreconditionError
+                      description:[NSString
+                                      stringWithFormat:@"The lablemap has no expected key %d.", i]];
+
+            return nil;
+          }
+          [labels addObject:[NSString stringWithCppString:options.label_items().at(i).name()]];
+        }
+      }
+    }
+  }
+  return labels;
+}
+
 + (nullable MPPImageSegmenterResult *)
     imageSegmenterResultWithOptionalOutputPacketMap:(std::optional<PacketMap> &)outputPacketMap
                            shouldCopyMaskPacketData:(BOOL)shouldCopyMaskPacketData {