C++ Demo - Image Classification (PPResNet) (#241)

* Functional version of C++ demo.

* Improve printout.

* Remove printouts and add README examples

* Add goldfish example

* Add empty space at EOF

* Add empty line at EOF for Python

* Use the shared labels.txt file instead of having the entire list as a variable in the demo.py

* Address PR comments. Revert example and labels

* Use namespaces for brevity

* Follow OpenCV formatting

* Remove LoadLabel() and use a vector of strings instead of having redundant work.

models/image_classification_ppresnet/CMakeLists.txt

@@ -0,0 +1,32 @@
+cmake_minimum_required(VERSION 3.24)
+set(project_name "opencv_zoo_image_classification_ppresnet")
+
+PROJECT (${project_name})
+
+set(OPENCV_VERSION "4.9.0")
+set(OPENCV_INSTALLATION_PATH "" CACHE PATH "Where to look for OpenCV installation")
+find_package(OpenCV ${OPENCV_VERSION} REQUIRED HINTS ${OPENCV_INSTALLATION_PATH})
+# Find OpenCV, you may need to set OpenCV_DIR variable
+# to the absolute path to the directory containing OpenCVConfig.cmake file
+# via the command line or GUI
+
+file(GLOB SourceFile
+    "demo.cpp")
+# If the package has been found, several variables will
+# be set, you can find the full list with descriptions
+# in the OpenCVConfig.cmake file.
+# Print some message showing some of them
+message(STATUS "OpenCV library status:")
+message(STATUS "    config: ${OpenCV_DIR}")
+message(STATUS "    version: ${OpenCV_VERSION}")
+message(STATUS "    libraries: ${OpenCV_LIBS}")
+message(STATUS "    include path: ${OpenCV_INCLUDE_DIRS}")
+
+# Declare the executable target built from your sources
+add_executable(${project_name} ${SourceFile})
+
+# Set C++ compilation standard to C++11
+set(CMAKE_CXX_STANDARD 11)
+
+# Link your application with OpenCV libraries
+target_link_libraries(${project_name} PRIVATE ${OpenCV_LIBS})

models/image_classification_ppresnet/README.md

@@ -15,14 +15,34 @@ Results of accuracy evaluation with [tools/eval](../../tools/eval).
 
 ## Demo
 
-Run the following command to try the demo:
+Run the following commands to try the demo:
+
+### Python
 
 ```shell
 python demo.py --input /path/to/image
 
 # get help regarding various parameters
 python demo.py --help
 ```
+### C++
+
+Install latest OpenCV and CMake >= 3.24.0 to get started with:
+
+```shell
+# A typical and default installation path of OpenCV is /usr/local
+cmake -B build -D OPENCV_INSTALLATION_PATH=/path/to/opencv/installation .
+cmake --build build
+
+# detect on an image
+./build/opencv_zoo_image_classification_ppresnet -i=/path/to/image
+
+# detect on an image and display top N classes
+./build/opencv_zoo_image_classification_ppresnet -i=/path/to/image -k=N
+
+# get help messages
+./build/opencv_zoo_image_classification_ppresnet -h
+```
 
 ## License