negative images

[tommy]

How do you convert QImage and QPixmap (that are grayscale) to negative mode? Is there a function for that?

[ashukla]

How do you convert QImage and QPixmap (that are grayscale) to negative mode? Is there a function for that?
What Do you mean by negative mode?

[wysota]

You have to negate each pixel in the image or negate each colour in the lookup table (depending on the mode of the image). To negate a grayscale color, you can use
int v = 255-qGray(color.rgb());
QColor result = QColor(v,v,v);

[aamer4yu]

Or you can use QImage::invertPixels :)