updated README, changed calculator name

README.md

@@ -154,3 +154,17 @@ We welcome contributions. Please follow these
 
 We use GitHub issues for tracking requests and bugs. Please post questions to
 the MediaPipe Stack Overflow with a `mediapipe` tag.
+
+
+## Steps to add an image_flip_calculator
+Objective of this exercise is to create a custom calculator which can do some custom prcessing of the image('flipping') and then insert this calculator in the mediapipe graph pipe line.
+Description: Calculators are the blocks of code which reperesent a node in a subgraph in mediapipe computational graphs.
+
+1. Goto /mediapipe/calculators/image directory , which contains several image manipulation calculators, place your custom calculator code in a .cc file right here.
+2. Edit the BUILD file in the same image folder by creating a <cc_library> entry for your calculator (the name is 'custom_calculator' in this case, mentioning the name the calculator  src file in last step in the <srcs> section).
+3. Edit the /mediapipe/modules/pose_landmark/pose_landmark_cpu.pbtxt , creating a <node> entry for your calculator by giving it a name ('CustomImageFlipCalculator' in this case, same as that of the class defined by the calculator in step 1. ) whose input willbe  the inputstream  of the graph and output will connect to the node previously connected to the original input stream)
+4. The node created in the step 3 will connect to you custom_calculator by making an entry in the  BUILD file in /mediapipe/modules/pose_landmark/ ; edit the file by finding the entry which mentions name <PoseLandmarkCpu> in the <register_as> section. <PoseLandmarkCpu> is the name of the sub_graph described by the   pose_landmark_cpu.pbtxt.
+In the 'deps' section, add the calculator entry as dependency to the subgraph(in  this case "//mediapipe/calculators/image:custom_calculator").
+5. BUILD your custom calculator by running 
+"bazel build -c opt --define MEDIAPIPE_DISABLE_GPU=1 mediapipe/calculators/image:custom_calculator" , and also for the pose_detection by running 
+"bazel build -c opt --define MEDIAPIPE_DISABLE_GPU=1 mediapipe/examples/desktop/pose_tracking:pose_tracking_cpu", and then run the pose detection desktop example.

mediapipe/calculators/image/image_flip_calculator.cc

@@ -59,7 +59,7 @@ using GpuBuffer = mediapipe::GpuBuffer;
 //     }
 //   }
 // }
-class AkashImageFlipCalculator : public Node {
+class CustomImageFlipCalculator : public Node {
  public:
   static constexpr Input<ImageFrame> kIn{"IMAGE"};
   static constexpr Output<ImageFrame> kOut{"IMAGE"};
@@ -125,7 +125,21 @@ class AkashImageFlipCalculator : public Node {
         input_mat = formats::MatView(&input);
         
         format = input.Format();
-            // code to flip
+        /*cv::Rect myROI(0, 0, output_width/2, output_height/2);
+        cv::Mat croppedRef(input_mat, myROI);
+        cv::Mat cropped;
+        croppedRef.copyTo(cropped);
+        cv::Mat imgPanel(480, 640, CV_8UC1, Scalar(0));
+        Mat imgPanelRoi(imgPanel, Rect(0, 0, imgSrc.cols, imgSrc.rows));
+        imgSrc.copyTo(imgPanelRoi);
+        cv::resize(cropped, input_mat, cv::Size(), 2, 2);
+        std::cout<<"size>>>>"<<input_mat.size;*/
+        
+
+
+
+            
+        // code to flip
         cv::flip(input_mat, flipped_mat, 1);
 // Use Flip code 0 to flip vertically
 
@@ -159,7 +173,7 @@ class AkashImageFlipCalculator : public Node {
   mediapipe::GlCalculatorHelper gpu_helper_;
 #endif  // !MEDIAPIPE_DISABLE_GPU
 };
-MEDIAPIPE_REGISTER_NODE(AkashImageFlipCalculator);
+MEDIAPIPE_REGISTER_NODE(CustomImageFlipCalculator);
 
 }  // namespace api2
 }  // namespace mediapipe

mediapipe/modules/pose_landmark/pose_landmark_cpu.pbtxt

@@ -130,10 +130,10 @@ node {
   }
 }
 
-# added by Akash
+# added by Akash for Image Flip Calculator
 
 node {
-  calculator: "AkashImageFlipCalculator"
+  calculator: "CustomImageFlipCalculator"
   input_stream: "IMAGE:image1"
   output_stream: "IMAGE:image"
 }