[vtkusers] Brightness

[bharathram.rambadran at wipro.com]

Hi,

I am working on changing brightness levels of an Image. I am using
Qt/e(embedded) libraries to help me in the process. So far I have
managed to load a image file in a Qpixmap and display it using a
Qcanvasview.

The depth of the Qpixmap is 16.
After,
QImage img = myPixmap.convertToImage().
The QImage's numcolors is only 2.

I have tried the following to adjust brightness. Since I am kind of new
to Qt. I am not sure if this is right. This does not work  and the image
seems to remain the same when I test it with various values.

oid TIQ_ImageDocument::adjustBrightness(int magnitude) {

    QImage img;
    img.setNumColors(65535);
    img = m_pmScaled.convertToImage();
    img.setNumColors(65535);

    img.detach();

    img.setNumColors(65535);

     for (i=0; i<img.numColors(); i++) {
            QRgb rgb = img.color(i);
            QColor c(rgb);
            rgb = c.dark(magnitude).rgb(); // magnitude was given as
300, 600 etc..
            img.setColor(i,rgb);
     }

     m_pmScaled.convertFromImage(img);

}

1)Is there anything I am assuming which I should not.
2)IS 65535 a good number?
3) is there a better way to change brightness of an image.

Regards
Bharath Ram
"Easy way to start flying: Throw yourself at the ground and Miss! "


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