Creating a shared object which depends on other sh

The Problem

I am creating a shared object (called libA.so) which uses OpenCV shared objects (for example libopencv_core.so).

Here's my shared object's code:

#include "opencv2/opencv.hpp"
#include "rgbframe.h"

#define API_EXPORT  __attribute__ ((visibility ("default")))
#define API_LOCAL  __attribute__ ((visibility ("hidden")))

using namespace cv;

API_EXPORT RGBFrame getFrame(int width, int height){
    VideoCapture cap(0);
    RGBFrame frame;

    if(!cap.isOpened())
        return frame;

    // Set camera resolution
    cap.set(CV_CAP_PROP_FRAME_WIDTH, width);
    cap.set(CV_CAP_PROP_FRAME_HEIGHT, height);

    frame.rows = height;
    frame.cols = width;
    frame.data = new uchar[frame.rows * frame.cols * 3];
    Mat mat(frame.rows, frame.cols, CV_8UC3, frame.data);

    // Get a frame
    cap >> mat;

    // Convert BGR to RGB
    cv::cvtColor(mat, mat, CV_BGR2RGB, 3);

    return frame;
}

Also here's how I compile it:

gcc -shared -fPIC -Wl,-soname,libA.so -std=c++11 -lpthread -lopencv_core -lopencv_video -lopencv_highgui -lopencv_imgproc -o libA.so test.cpp

Therefore from the line above, we know that libA.so depends on opencv_core, opencv_video and so forth.

It compiles and links fine, but when I ldd libA.so, it prints:

linux-vdso.so.1 =>  (0x00007ffc71b76000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f074cbaa000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f074c7e3000)
/lib64/ld-linux-x86-64.so.2 (0x000055b29e8bd000)

meaning that my library doesn't depend on OpenCV .so files. Apart from this, when I use my library in a simple program, the whole program won't compile. There will be a bunch of undefined reference to OpenCV functions I have used in libA.so.