Configure OpenCV for Android and manipulate image HSV

Hey Guys,

Just used OpenCV in  one of my project to manipulate image Hue, Saturation and Brightness.

Here is source code:
//**************************//
In Java class:
//Image input
InputStream is;
is = this.getResources().openRawResource(R.drawable.img_test);
Bitmap bmInImg = BitmapFactory.decodeStream(is);

int[] mPhotoIntArray;
int[] mOutArray;

mPhotoIntArray = new int[bmInImg.getWidth() * bmInImg.getHeight()];
// Copy pixel data from the Bitmap into the 'intArray' array
bmInImg.getPixels(mPhotoIntArray, 0, bmInImg.getWidth(), 0, 0, bmInImg.getWidth(), bmInImg.getHeight());

// create the canny result buffer
mOutArray= new int[bmInImg.getWidth() * bmInImg.getHeight()];

hsb(bmInImg.getHeight(), bmInImg.getWidth(), h,s,b, mPhotoIntArray, mOutArray);

//use recived output
Bitmap bmOutImg = Bitmap.createBitmap(bmInImg.getWidth(), bmInImg.getHeight(), Config.ARGB_8888);
bmOutImg.setPixels(mOutArray, 0, bmInImg.getWidth(), 0, 0, bmInImg.getWidth(), bmInImg.getHeight());
img.setImageBitmap(bmOutImg);


public native boolean hsb(int width, int height, double hueEffect,double satrEffect,double brightnessEffect, int[] mPhotoIntArray, int[] mOutArray);


static
{
System.loadLibrary("first-opencv");
}

//**************************//
JNI file:

#include <jni.h>

#include <opencv/cv.h>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc_c.h>
#include <android/log.h>
using namespace cv;

//jboolean - return type
// Java - jni notation
// com_deepapps_ui - package name of class in which method loaded/declared.
// EditorFragmentActivity - class in  the package.
// hsb - method name

extern "C" jboolean Java_com_deepapps_ui_EditorFragmentActivity_hsb(
JNIEnv* env, jobject thiz, jint width, jint height, jdouble hueEffect,
jdouble saturationEffect, jdouble brightnessEffect, jintArray in,
jintArray out) {
//get the data pointer.
IplImage *hsv, *hue, *sat, *val, *b, *r, *g, *brg;
double scale = 1;
int key = 0, depth;
CvSize size;

jint* _in = env->GetIntArrayElements(in, 0);
jint* _out = env->GetIntArrayElements(out, 0);

//Build the Mat structure for input data
Mat mSrc(height, width, CV_8UC4, (unsigned char *) _in);
//Build the Mat structure for output data
Mat mOut(height, width, CV_8UC4, (unsigned char *) _out);

//Convert Mat to IplImage
IplImage mSrcImg = mSrc;
IplImage mOutImg = mOut;

if (mSrcImg.nChannels != 3) {
printf("image is not compatible to precess!");
exit - 1;
}

size = cvGetSize(&mSrcImg);
depth = mSrcImg.depth;
hue = cvCreateImage(size, depth, 1);
sat = cvCreateImage(size, depth, 1);
val = cvCreateImage(size, depth, 1);
hsv = cvCreateImage(size, depth, 3);
cvZero(hsv);
cvZero(hue);
cvZero(sat);
cvZero(val);
b = cvCreateImage(size, depth, 1);
r = cvCreateImage(size, depth, 1);
g = cvCreateImage(size, depth, 1);
brg = cvCreateImage(size, depth, 3);
cvZero(brg);
cvZero(hue);
cvZero(sat);
cvZero(val);
IplImage *im1_a = cvCreateImage(cvGetSize(&mSrcImg), 8, 1); //hold alpha chanel
IplImage *im1_bgra = cvCreateImage(cvGetSize(&mSrcImg), 8, 4);
/* Convert from Red-Green-Blue to Hue-Saturation-Value */
cvCvtColor(&mSrcImg, im1_bgra, CV_BGR2BGRA);
cvCvtColor(&mSrcImg, hsv, CV_BGR2HSV);

/* Split hue, saturation and value of hsv on them */
cvSplit(im1_bgra, hue, sat, val, im1_a);
cvSplit(hsv, hue, sat, val, 0);

cvConvertScale(hue, hue, scale, hueEffect); //update hue // (uchar) ((double)src*scale+saturation)
cvConvertScale(sat, sat, scale, saturationEffect); //update sat

cvMerge(hue, sat, val, 0, hsv);
cvCvtColor(hsv, brg, CV_HSV2BGR);

cvSplit(brg, b, g, r, 0);
cvMerge(b, g, r, im1_a, &mOutImg);//merge b g r and orignal apha

mOut = &mOutImg
+ Scalar(brightnessEffect, brightnessEffect, brightnessEffect); //update brightness

__android_log_write(ANDROID_LOG_ERROR, "satr", "4");
//release the pointer.
env->ReleaseIntArrayElements(in, _in, 0);
env->ReleaseIntArrayElements(out, _out, 0);
return true;
}


Put this code in "open-cv.cpp" under jni folder.( jni should be in root folder of project)

Create Android.mk file in jni folder and put:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCV_INSTALL_MODULES:=on
OPENCV_CAMERA_MODULES:=off
OPENCV_LIB_TYPE:=STATIC
include ..replacewithopencvfolderpath\sdk\native\jni\OpenCV.mk
LOCAL_MODULE    := open-cv
LOCAL_SRC_FILES := open-cv.cpp
LOCAL_LDLIBS +=  -llog -ldl
include $(BUILD_SHARED_LIBRARY)

Create Application.mk in jni folder and put:

APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi-v7a
APP_PLATFORM := android-9
APP_MODULES := open-cv





//make sure your sourcecode and opencv libs folders path must be without space in there name.

Download opencv from: http://sourceforge.net/projects/opencvlibrary/files/opencv-android/2.4.9/OpenCV-2.4.9-android-sdk.zip/download

I hope you must have android ndk configured in your eclipse.
Or follow steps: https://developer.android.com/tools/sdk/ndk/index.html


Android project properties:
-> C/C++ build
Builder setting -> build command : ndk-build

-> C/C++ General Setting
  Path and Symbol
Add:
1. ..ndkfolderpath\sources\cxx-stl\system\include
2. ..ndkfolderpath\sources\cxx-stl\gnu-libstdc++\4.6\include
3. ..ndkfolder\platforms\android-9\arch-arm\usr\include
4  ..opencvfolder\sdk\native\jni\include

Let me know if have any doubt.


keywords: opencv android, android jni, Hue , Saturation, Brightness, Image color manipulation, android NDK