[fitsbits] Question(s) regarding development of proprietary FITS manipulation software. . .

[gberz3]

The silence is deafening. . .

Alright all.  I suppose I was asking the right question(s) in the
wrong manner in the beginning.  I have now actually figured out how to
interpret 2-D image data.  The information literally has to be read in
8-byte increments and converted to a double.  That will then allow me
to map RGB pixel data to a buffer.

*THAT* is what I needed to know.  How to read in and interpret the
data.  I had *NO* idea what that "garbage" was supposed to mean or how
many chickens I needed to sacrifice in order to get it to work.

Anyway, thanks to all that contributed.  My apologies for any
confusion.

Regards,
Michael

On Aug 27, 10:38 am, Michael Williams <gbe... at gmail.com> wrote:
> Ok, I actually asked a follow-on question in another post/e-mail.  
> Basically I asked if these astronomers images were literally live  
> images (perhaps of the stars, or nieces and nephews), or if they were  
> simply arbitrary graphical representations of data that had no  
> reference in reality.  Also, given the fact that, as you said,  
> reverse transformation isn't always possible, why in the world does  
> it matter if the user can perform image manipulations of any type?  I  
> mean, if there is no consistent way to produce an image, then why do  
> we care?
>
> Thanks,
> Michael
>
> On Aug 27, 2007, at 5:15 AM, Thierry Forveille wrote:
>
> > gberz3 a écrit :
> >> Why would *anyone* present FITS data as images if they are
> >> not image data?  Why not represent it as sound?
> >> I guess that's what I'm getting at.  What relevance does an image  
> >> have
> >> to actual FITS data if there is no "attached" image, and what is the
> >> proper means by which to display said image?
> > The issue is mostly your notion of an image, vs an astronomer's
> > notion of the same. To you an image is something that can be
> > univocally displayed on a screen or printed, while to
> > astronomers it is a set of values (ideally in physical units,
> > such as Watts per square meter per steradian) sampled on a
> > regular grid. There is some link between the two notions,
> > but not a unique one: an astronomer's image can be displayed
> > but not in one unique way, and the reverse transformation
> > if/when at all possible, requires additional information
> > (e.g. the physical values for a subset of the pixels) and
> > significant calibration work. Essentially, an astromer's
> > image is a richer dataset, and someone needs to decide how
> > to degrade that information to what a display can show.
>
> > In addition, images (in the astronomer's definition) is only
> > one of the data classes that can be stored in FITS.