Added iOS MPPMask test utils

mediapipe/tasks/ios/test/vision/utils/BUILD

@@ -12,6 +12,16 @@ objc_library(
         "//mediapipe/tasks/ios/test/utils:MPPFileInfo"],
 )
 
+objc_library(
+    name = "MPPMaskTestUtils",
+    srcs = ["sources/MPPMask+TestUtils.m"],
+    hdrs = ["sources/MPPMask+TestUtils.h"],
+    module_name = "MPPMaskTestUtils",
+    deps = [
+        "//mediapipe/tasks/ios/vision/core:MPPMask",
+        "//mediapipe/tasks/ios/test/utils:MPPFileInfo",
+        "//third_party/apple_frameworks:UIKit",
+    ]
 )
 
 cc_library(

mediapipe/tasks/ios/test/vision/utils/sources/MPPMask+TestUtils.h

@@ -0,0 +1,42 @@
+// Copyright 2023 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.
+
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+#import "mediapipe/tasks/ios/test/utils/sources/MPPFileInfo.h"
+#import "mediapipe/tasks/ios/vision/core/sources/MPPMask.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * Helper utility for initializing `MPPMask` for MediaPipe iOS vision library tests.
+ */
+@interface MPPMask (TestUtils)
+
+/**
+ * Loads an image from a file in an app bundle and Creates an `MPPMask` of type
+ * `MPPMaskDataTypeUInt8` using the gray scale pixel data of a `UIImage` loaded from a file with the
+ * given `MPPFileInfo`.
+ *
+ * @param fileInfo The file info specifying the name and type of the image file in the app bundle.
+ *
+ * @return The `MPPMask` with the pixel data of the loaded image. This method returns `nil` if there
+ * is an error in loading the image correctly.
+ */
+- (nullable instancetype)initWithImageFileInfo:(MPPFileInfo *)fileInfo;
+
+@end
+
+NS_ASSUME_NONNULL_END

mediapipe/tasks/ios/test/vision/utils/sources/MPPMask+TestUtils.m

@@ -0,0 +1,63 @@
+// Copyright 2023 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.
+
+#import "mediapipe/tasks/ios/test/vision/utils/sources/MPPMask+TestUtils.h"
+
+@implementation MPPMask (TestUtils)
+
+- (instancetype)initWithImageFileInfo:(MPPFileInfo *)fileInfo {
+  UIImage *image = [[UIImage alloc] initWithContentsOfFile:fileInfo.path];
+
+  if (!image.CGImage) {
+    return nil;
+  }
+
+  size_t width = CGImageGetWidth(image.CGImage);
+  size_t height = CGImageGetHeight(image.CGImage);
+
+  NSInteger bitsPerComponent = 8;
+
+  UInt8 *pixelData = NULL;
+
+  CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
+
+  // For a gray scale image (single component) with no alpha, the bitmap info is
+  // `kCGImageAlphaNone` in combination with bytesPerRow being equal to width.
+  CGContextRef context = CGBitmapContextCreate(nil, width, height, bitsPerComponent, width,
+                                               colorSpace, kCGImageAlphaNone);
+
+  if (!context) {
+    CGColorSpaceRelease(colorSpace);
+    return nil;
+  }
+
+  CGContextDrawImage(context, CGRectMake(0, 0, width, height), image.CGImage);
+  pixelData = (UInt8 *)CGBitmapContextGetData(context);
+
+  // A copy is needed to ensure that the pixel data outlives the `CGContextRelease` call.
+  // Alternative is to make the context, color space instance variables and release them in
+  // `dealloc()`. Since Categories don't allow adding instance variables, choosing to copy rather
+  // than creating a new custom class similar to `MPPMask` only for the tests.
+  MPPMask *mask = [[MPPMask alloc] initWithUInt8Data:pixelData
+                                               width:width
+                                              height:height
+                                          shouldCopy:YES];
+
+  CGColorSpaceRelease(colorSpace);
+  CGContextRelease(context);
+
+  return mask;
+}
+
+@end