android 中bimap转mat例程

#include <jni.h>
#include <android/log.h>
#include <android/bitmap.h>

#define  LOG_TAG    "test"
#define  LOGI(...)  __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
#define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)

/*
test for color transform
*/
JNIEXPORT void JNICALL Java_com_wzh_test_NDKTestActivity_convertToGray(JNIEnv
* env, jobject  obj, jobject bitmapcolor)
{
    AndroidBitmapInfo  infocolor;
    void*              pixelscolor;
    int                ret;
 
    LOGI("convertToGray");
    if ((ret = AndroidBitmap_getInfo(env, bitmapcolor, &infocolor)) < 0) {
        LOGE("AndroidBitmap_getInfo() failed ! error=%d", ret);
        return;
    }

    LOGI("color image :: width is %d; height is %d; stride is %d; format is %d;flags is %d",
            infocolor.width,infocolor.height,infocolor.stride,infocolor.format,infocolor.flags);
    if (infocolor.format != ANDROID_BITMAP_FORMAT_RGBA_8888) {
        LOGE("Bitmap format is not RGBA_8888 !");
        return;
    }


    if ((ret = AndroidBitmap_lockPixels(env, bitmapcolor, &pixelscolor)) < 0) {
        LOGE("AndroidBitmap_lockPixels() failed ! error=%d", ret);
    }

    Mat test(heigth,width,CV_8UC4,infocolor);
    Mat bgra;

    Mat bgr;

    Mat rgba;

    //转换成BGRA
    cvtColor(test,bgra,CV_RGBA2BGRA);
    //转换成BGR
    cvtColor(test,bgr,CV_RGBA2BGR);
    //从BGR转换回RGBA，可再将数据拷贝回bitmap
    cvtColor(test,rgba,CV_BGR2RGBA);
    AndroidBitmap_unlockPixels(env, bitmapcolor);
}