Image processing in OpenGL

[ArtemVas]

Hello.
I want to process the image and save it. Wrote this code, but the output is a black image. What am I doing wrong?

void ImageProcessor::startProcessing()
{
    QSurfaceFormat surFormat;

    QOpenGLContext context;
    context.setFormat(surFormat);

    if(!context.create())
        return;

    QOffscreenSurface surface;
    surface.setFormat(surFormat);
    surface.create();

    if(!context.makeCurrent(&surface))
        return;

    auto func = QOpenGLContext::currentContext()->functions();

    QOpenGLFramebufferObjectFormat format;
    format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);

    QOpenGLFramebufferObject fbo(1000, 1000, format);

    fbo.bind();

    func->glClearColor(0, 0, 0, 1);

    QOpenGLTexture *texture = new QOpenGLTexture(m_imageIn.mirrored(), 
    QOpenGLTexture::MipMapGeneration::DontGenerateMipMaps);
    if(!texture->create())
        return;
    texture->bind();
    texture->release();

    fbo.release();

    m_imageOut = fbo.toImage();

    emit finishProcessing();
}

[SGaist]

Hi and welcome to devnet,

Where are you calling this code from ?