Re: [boost] [gil] IMC4 Pixel format

Subject: Re: [boost] [gil] IMC4 Pixel format
From: Christian Henning (chhenning_at_[hidden])
Date: 2013-03-14 11:20:12

Hi,

thanks for you interest in boost::gil!

On Thu, Mar 14, 2013 at 10:48 AM, Harg Tholan <hargtholan_at_[hidden]> wrote:
> Hey,
>
> I've been trying to find a definition for the
> IMC4<http://www.fourcc.org/yuv.php#IMC4>pixel format for GIL with no
> success, not even anything similar (planar
> pixel formats in which some of the channels are sub-sampled).

There are some color spaces in the toolbox, like xyz, lab, hsl, hsv,
etc. Not sure if any of those can help you out. The toolbox has been
added to boost trunk and should be released either with the next
release or the following one.

Could you give me some insight in how a yuv pixel could be defined?
Like what are the bit sizes for each channel, for instance.

>
> I've spent many hours already trying to figure out how could I create such
> pixel format, and I am totally lost...

I'm sorry to hear that. I'm here to help but I have to concede that
I'm not an expert in your field. So it could mutually benefiting. ;-)

>
> The question is how can I specify that a pixel format is planar, and planes
> have different sizes due to sub-sampling!....I guess I'll have to override
> some operator[] operator++, operator-- Or to make a specialization of some
> classes.
>
> But how and where? planar_pixel_iterator? channel_iterator?
> I need some aid! please!

Let's start at the beginning, like defining the pixel time. I can help
and spell your code into gil code if necessary.

Regards,
Christian