Answer's Engineering Blog: [ Raspberry Pi2 ] OpenCV using Picam 3

We saved jpg file in Previous posting.

This posting is about OpenCV.

1. Install OpenCV and related packages.

Install GTK + UVC viewer.

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sudo apt-get install guvcview
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Setting uvcvideo.

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sudo usermod -a -G video pi

sudo modprobe uvcvideo
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Install OPENCV library.

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sudo apt-get install libopencv-dev
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Install Python-Opencv.

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sudo apt-get install python-opencv
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Install face recognition

face recognition Download

If above link is didn't download, use below link.

face recognition Download

Extract to home/pi/ (using samba is easy)

You can see 'bytefish-libfacerec-xxx' folder in extract folder.

You move to /home/pi/ and rename 'bytefish-libfacerec '.

2. BUILD

cmake

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cd ..

cd bytefish-libfacerec

sudo cmake .
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make

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sudo make
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If build is success, make this file libopencv_facerec.a

move folder to /home/pi/camcv/libfacerec/

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mkdir /home/pi/camcv/libfacerec

cd /home/pi/camcv/libfacerec

cp -r /home/pi/bytefish-libfacerec/* .  

cd ..

Colored by Color Scripter
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Editing makelist

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sudo nano CMakeLists.txt
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Recommend all text copy.

cmake_minimum_required(VERSION 2.8)
project(camcv)
SET(COMPILE_DEFINITIONS -Werror)
#OPENCV
find_package( OpenCV REQUIRED )
#except if you’re pierre, change the folder where you installed libfacerec
#optional, only if you want to go till step 6 : face recognition
link_directories( /home/pi/camcv/libfacerec)
include_directories(/opt/vc/include)
include_directories(/opt/vc/include/interface/vcos)
include_directories(/opt/vc/include/interface/vcos/pthreads)
include_directories(/opt/vc/include/interface/vmcs_host/linux)
include_directories(.)
include_directories(/opt/vc/userland/host_applications/linux/libs/bcm_host/include)
include_directories(/opt/vc/userland/interface/vcos)
include_directories(/opt/vc/userland)
include_directories(/opt/vc/userland/interface/vcos/pthreads)
include_directories(/opt/vc/userland/interface/vmcs_host/linux)
include_directories(/opt/vc/userland/interface/khronos/include)
include_directories(/opt/vc/userland/interface/khronos/common)
include_directories(/home/pi/camcv/)
include_directories(/home/pi/camcv/gl_scenes/)
include_directories(/home/pi/camcv/libfacerec/include/)
add_executable(camcv RaspiCamControl.c RaspiCLI.c RaspiPreview.c camcv.c RaspiTex.c RaspiTexUtil.c gl_scenes/teapot.c
gl_scenes/models.c gl_scenes/square.c gl_scenes/mirror.c gl_scenes/sobel.c gl_scenes/yuv.c tga.c )
target_link_libraries(camcv /opt/vc/lib/libmmal_core.so /opt/vc/lib/libmmal_util.so /opt/vc/lib/libmmal_vc_client.so /opt/vc/lib/libvcos.so /opt/vc/lib/libbcm_host.so /opt/vc/lib/libGLESv2.so /opt/vc/lib/libEGL.so libpthread.so libm.so /home/pi/camcv/libfacerec/libopencv_facerec.a ${OpenCV_LIBS})

Editing camcv.c

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sudo nano camcv.c
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Lines 61+ : add OpenCV Includes
// *** PR : ADDED for OPENCV
#include <cv.h>
#include <highgui.h>
Line 156 : modify init values for test (size of file)
// *** PR : modify for demo purpose : smaller image
state->timeout = 1000; // 5s delay before
take image
state->width = 320;//2592;
state->height = 200; //1944;
Line 230+ : in static void encoder_buffer_callback function.
This is the core of the modification.
This function is a callback, call to get the image in the queue.
buffer contains the picture from the camera.
// *** PR : OPEN CV Stuff here !
// create a CvMat empty structure, with size of the buffer.
CvMat* buf = cvCreateMat(1,buffer->length,CV_8UC1);
// copy buffer from cam to
CvMatbuf->data.ptr = buffer->data;
// decode image (interpret jpg)
IplImage *img = cvDecodeImage(buf, CV_LOAD_IMAGE_COLOR);
// we can save it
!cvSaveImage(“foobar.bmp”, img,0);
// or display it
cvNamedWindow(“camcvWin”, CV_WINDOW_AUTOSIZE);
cvShowImage(“camcvWin”, img );
cvWaitKey(0);
Line 711/726/823 : we remove the native preview window (replaced by opencv window)
// *** PR : we don’t want preview
camera_preview_port = NULL;
// PR : we don’t want preview
// status = connect_ports(camera_preview_port, preview_input_port, &state.preview_connection);
// mmal_connection_destroy(state.preview_connection);