
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<uint64_t, 04, 12, true> rgb12_packed_channel0_t; typedef const packed_channel_reference<uint64_t, 20, 12, true> rgb12_packed_channel1_t; typedef const packed_channel_reference<uint64_t, 36, 12, true> rgb12_packed_channel2_t; typedef mpl::vector3<rgb12_packed_channel0_t, rgb12_packed_channel1_t, rgb12_packed_channel2_t> rgb12_packed_channels_t; typedef packed_pixel<packed_channel_value<48>, rgb12_packed_channels_t, rgb_layout_t> rgb12_packed_pixel_t; typedef view_type_from_pixel<rgb12_packed_pixel_t>::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.

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 <eloi.du.bois@gmail.com> wrote:

Hi Eloi, Try calling copy_and_convert_pixels. I believe it does what you want. Lubomir From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Eloi Du Bois Sent: Wednesday, December 16, 2009 2:18 AM To: boost-users@lists.boost.org Subject: [Boost-users] [GIL] Packing to 6 bytes 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<uint64_t, 04, 12, true> rgb12_packed_channel0_t; typedef const packed_channel_reference<uint64_t, 20, 12, true> rgb12_packed_channel1_t; typedef const packed_channel_reference<uint64_t, 36, 12, true> rgb12_packed_channel2_t; typedef mpl::vector3<rgb12_packed_channel0_t, rgb12_packed_channel1_t, rgb12_packed_channel2_t> rgb12_packed_channels_t; typedef packed_pixel<packed_channel_value<48>, rgb12_packed_channels_t, rgb_layout_t> rgb12_packed_pixel_t; typedef view_type_from_pixel<rgb12_packed_pixel_t>::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.
participants (3)
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Christian Henning
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Eloi Du Bois
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Lubomir Bourdev