Subject: Re: [Boost-users] [GIL] wrapper for QImage
From: Tomas Van Verrewegen (tomasvanverrewegen_at_[hidden])
Date: 2009-02-22 06:35:46
> I don't think I'm copying back and forth.
Maybe I misinterpreted the call to
cvSetData( img
, &view.begin()[0]
, num_channels<View>::value * view.width() * sizeof( channel_t ));
> Can you get access to the image buffer, scanline length, etc?
These should do the trick:
uchar * QImage::bits ()
const uchar * QImage::bits () const
int QImage::bytesPerLine () const
int QImage::depth () const
QImage::Format QImage::format () const
int QImage::height () const
int QImage::width () const
So I can get a pointer to the image buffer. In the case of an ARGB8 image this
pointer can be cast to QRgb* (which is a typedef for unsigned int).
A (class modelling) PixelIteratorConcept should return a (class modelling)
PixelConcept on dereference. unsigned int does not model PixelConcept, so I
suppose I need to create a proxy class that does model PixelConcept...
What I need to implement is this (please correct me if I'm mistaken):
// a pixel in a QImage
// models PixelConcept
template<QImage::Format Format> struct qimage_pixel {
// ...
}
// iterate over the pixels of a QImage
// models PixelIterator/MutablePixelIterator
template<QImage::Format Format> struct qimage_pixel_iterator;
template<QImage::Format Format> struct qimage_const_pixel_iterator;
// for every member of QImage::Format:
template<QImage::Format Format>
type_from_x_iterator<qimage_pixel_iterator<Format> >::view_t
qimage_view(const QImage& image) {
return interleaved_view(
image.width(),
image.height(),
qimage_iterator<Format>(image.bits()),
image.bytesPerLine()
);
}
// specialize some traits classes (const_iterator_type, channel_type,
// color_space_type, ...) for qimage_pixel and qimage_pixel_iterator