I'd like to try this out a bit. I loaded a file that was 720 x 480 and set
the xPixels and yPixels to 720 x 480 but the image only appeared in the
upper right quadrant. Now I see the Resx and Resy  factors. Should I set
xPixels and yPixels to the exact size of the input file and leave Resx as =
xPixels and the same for Resy to get the image to fill the screen?
thanks much
D.




; // actual size takes too long to render
#declare Resy = yPixels/2;
"normdoering" <nor### [at] yahoocom> wrote in message
news:web.3dcf7587da80818e1dffbb4f0@news.povray.org...
> In my quest to write some macros that can turn special 2D pencil drawings
> into mesh2 models (like human figures and faces that are photographically
> real) I've figured out how to read an imported picture pixel by pixel.
>
> However, I'd also like to know how to get a picture's size in pixels using
a
> POV feature (if there is any) because right now I'm reading those from
> Corel and typing them in.
>
> Here's the scene file:
>
> //=================================================================
> #version 3.5;
> #include "colors.inc"
> global_settings { assumed_gamma 1.0 }
> // ----------------------------------------
>
> camera
> { location  <0, 0, -850.0>
>   look_at   <0, 0, 0>
>   angle 35
> }
> background {rgb <0.5, 0.5, 0.5>}
>
> //No light source needed to test these assumptions uses ambient finish
> // -----------------------------
> // the test:
> //==============================
> #declare xPixels = 271; // 271 is number of pixels in x dimension
> #declare yPixels = 496; // 496 in y dimension
> // ---> How do I get these numbers without having to declare them?
> // That is, how can I ask for the size of an image in pixels?
>
> #declare ScX = 1;    // scale has to be declared because it's shared with
> the
> #declare ScY = 1.83; // #while loop. Difference in scale because the
> function
>                      // wants to create a square picture and fills the
> square
>                      // area from (x,y) coordinates (0,0) to (1,1)
> regardless
>                      // of the image's original size in pixels.
>
> // these mark how the picture goes exactly to upper right quadrant
> cylinder {-200*x, 200*x, 1 pigment {rgb <1,1,0>} finish {ambient 1}}
> cylinder {-200*y, 200*y, 1 pigment {rgb <1,1,0>} finish {ambient 1}}
>
>
> #declare MyTesti = function    // In order to get the HF_ macros to read
> { pigment                      // imported pictures they have to be
>   { image_map                  // declared this way.
>     { jpeg "12.jpg" map_type 0 // <----
>       once
>     }
>     scale <ScX, ScY, 1>
>   }
> }
> #declare MyTest = function {MyTesti(x,y,z).grey} // then redeclared
>                                                  // because
>                                                  // they're the wrong data
>                                                  // type
> #declare Resx = xPixels/6; // actual size takes too long to render
> #declare Resy = yPixels/6; // so I divide it by 6
>
> #declare incx = 1/Resx;
> #declare incy = 1/Resy;
>
> #declare yloc = 0;            // This loop can read a picture one pixel at
a
> #while (yloc < ScY + 0.0001)  // time.
> #declare xloc = 0;
> #while (xloc < ScX + 0.0001)
>
> sphere
>  { <xloc*50, yloc*50, -5> 0.5
>    pigment { rgb <MyTest(xloc,yloc,0), MyTest(xloc,yloc,0),
> MyTest(xloc,yloc,0)>}
>    finish {ambient 1}
>  }
>
> #declare xloc = xloc+incx;
> #end
> #declare yloc = yloc+incy;
> #end
> //=================================================================
>
> The above code will read a picture, potentially pixel by pixel, and copy
it
> to a structure made of spheres.
>
> -- normdoering
>
>
>

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