java glReadpixels到OpenCV mat

时间:2015-06-23 12:29:58

标签: java opencv opengl lwjgl framebuffer

我使用lwjgl在OpenGL中渲染图像,现在我想将Framebuffer的内容作为RGB存储在OpenCV矩阵中。为了使shure一切正常,我在jFrame的Panel上显示捕获的图像。 但继承人的问题是:虽然显示存储的jpegs一切看起来都很好,但如果我试图显示捕获的Framebuffer我只看到条纹!

Exemplary stripes

以下是截图的代码:

public Mat takeMatScreenshot()
{
    int   width       = m_iResolutionX;
    int   height      = m_iResolutionY;
    int   pixelCount  = width * height;
    byte[] pixelValues = new byte[ pixelCount * 3 ];

    ByteBuffer pixelBuffer = BufferUtils.createByteBuffer( width * height * 3 );

    glBindFramebuffer( GL_FRAMEBUFFER, m_iFramebuffer );
    glReadPixels( 0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, pixelBuffer );

    for( int i = 0; i < pixelCount; i++ )
    {
        int line        = height - 1 - (i / width); // flipping the image upside down
        int column      = i % width;
        int bufferIndex = ( line * width + column ) * 3;

        pixelValues[bufferIndex + 0 ] = (byte)(pixelBuffer.get(bufferIndex + 0) & 0xFF) ;
        pixelValues[bufferIndex + 1 ] = (byte)(pixelBuffer.get(bufferIndex + 1) & 0xFF);
        pixelValues[bufferIndex + 2 ] = (byte)(pixelBuffer.get(bufferIndex + 2) & 0xFF);
    }

    Mat image = new Mat(width, height, CvType.CV_8UC3);
    image.put(0, 0, pixelValues);

    new ImageFrame(image);

    return image;
}

这里是显示Mat的代码:

public static Image toBufferedImage(Mat m)
{
   int type = BufferedImage.TYPE_BYTE_GRAY;

   if ( m.channels() == 3 )
       type = BufferedImage.TYPE_3BYTE_BGR;

   if( m.channels() == 4 )
       type = BufferedImage.TYPE_4BYTE_ABGR;

   int bufferSize = m.channels()*m.cols()*m.rows();
   byte [] b = new byte[bufferSize];
   m.get( 0, 0, b ); // get all the pixels

   BufferedImage image = new BufferedImage( m.cols(), m.rows(), type );
   final byte[] targetPixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
   System.arraycopy(b, 0, targetPixels, 0, b.length);  
   return image;
}

如果有任何人可以帮助我的话会很棒! 干杯!

1 个答案:

答案 0 :(得分:0)

哦不!捂脸! OpenCV Mat对象的构造函数是:Mat(rows,cols)! 所以正确的解决方案是:

Mat image = new Mat(height, width, CvType.CV_8UC3);
image.put(0, 0, pixelValues);