Hi Eloi, I'm not sure if I can following here. How many channels do you have? How big is the channel size including the the 4 bits? Couldn't you just create a 64bit ( assuming 4 channels by ( 12 + 4 bits ) per channels ) pixel type and when looping through all channels per pixel you blend out ( using & operator with 0x0FFF ) the unwanted bits? Sorry, when my explanation is a bit cryptic. Kinda busy right now. Regards, Christian On Wed, Dec 16, 2009 at 5:17 AM, Eloi Du Bois wrote:

Hi,

I have a question: I need to create a view that hold 12 bit channel data packed as follow:

0000R0000G0000B0000;0000R0000G0000B0000;0000R0000G0000B0000;.... Meaning that each channel is shifted by 4 bits. The pixel is holden on 48 bits = 6 bytes.

I have created my view like as follow: /// My 12 bits special rgb packed to 6 bytes typedef const packed_channel_reference rgb12_packed_channel0_t; typedef const packed_channel_reference rgb12_packed_channel1_t; typedef const packed_channel_reference rgb12_packed_channel2_t; typedef mpl::vector3 rgb12_packed_channels_t; typedef packed_pixel, rgb12_packed_channels_t, rgb_layout_t> rgb12_packed_pixel_t; typedef view_type_from_pixel::type rgb12_packed_view_t;

The thing is that I would now like to copy data to another rgb16_view_t... But this is not working because, in my opinion, 48 bits is between 32 and 64. I have been thinking of the solution that Christian gave me and that consist on doing something like this:     T p( pData, 0 );

    for( typename DST_V::y_coord_t y = 0; y < height; ++y )     {         typename DST_V::x_iterator it = dst.row_begin( y );

        for( typename DST_V::x_coord_t x = 0; x < width; ++x )         {             color_convert( *p, *it );             ++p;             ++it;         }     }

where T is a bit_aligned_pixel_iterator and DST_V=rgb16_view_t but this can't be working on my case because channels are shifted by 4 bits !

If you could help me, I would really appreciate. I think all those cases are a good robustness test for gil.

Regards, Eloi.

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