displaycontours.c

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#include <stdio.h>
#include <math.h>
#include "basic.h"
#include "imageio.h"
#include "dmbilinear.h"
#include "mstencils.h"
#include "psio.h"

#define ROUNDCLAMP(X) (((X) < 0) ? 0 : (((X) > 1) ? 255 : floor(X*255 + 0.5f)))


int DisplayContours(const float *Image, int Width, int Height,
    int RedX, int RedY, const char *OutputFile)
{
    const int NumPixels = Width*Height;
    FILE *File = NULL;
    float *Mosaic = NULL;
    int *Stencil = NULL;
    uint8_t *ImageU8 = NULL;
    float Temp, x1, y1, x2, y2;
    int i, x, y, DimScale = 5, Success = 0;
    
    if(!(Mosaic = (float *)Malloc(sizeof(float)*NumPixels))
        || !(Stencil = (int *)Malloc(sizeof(int)*NumPixels))
        || !(ImageU8 = (uint8_t *)Malloc(sizeof(uint8_t)*3*NumPixels))
        /* Start an EPS file with DimScale*Width by DimScale*Height canvas */
        || !(File = PsOpen(OutputFile, 0, 0,
            DimScale*Width, DimScale*Height)))
        goto Catch;

    CfaFlatten(Mosaic, Image, Width, Height, RedX, RedY);
    /* Estimate the contour orientations */
    FitMosaicedStencils(Stencil, Mosaic, Width, Height, RedX, RedY);

    /* Lighten the image according to 0.5 + 0.5*Image and convert to
       unsigned 8-bit data.                                          */
    for(i = 0; i < NumPixels; i++)
    {
        Temp = 0.5f + 0.5f*Image[i];
        ImageU8[3*i + 0] = (uint8_t)ROUNDCLAMP(Temp);
        Temp = 0.5f + 0.5f*Image[i + NumPixels];
        ImageU8[3*i + 1] = (uint8_t)ROUNDCLAMP(Temp);
        Temp = 0.5f + 0.5f*Image[i + 2*NumPixels];
        ImageU8[3*i + 2] = (uint8_t)ROUNDCLAMP(Temp);
    }

    /* Set distiller parameters for PDF conversion */
    if(!PsSetDistillerParams(File,"/AutoFilterColorImages false "
        "/ColorImageFilter /FlateEncode"))
        goto Catch;
    /* Define PS macros and rescale canvas by DimScale */
    fprintf(File,"/bdef {bind def} bind def\n"
        "/m1 {moveto rlineto stroke} bdef\n"
        "0.08 setlinewidth\n"
        "%d %d scale\n", DimScale, DimScale);
    
    /* Write the image data ImageU8 into the EPS file */
    if(!PsWriteColorImage(File, ImageU8, Width, Height))
        goto Catch;
    
    /* Draw the contour orientations on top of the image */
    for(y = 0, i = 0; y < Height; y++)
        for(x = 0; x < Width; x++, i++)
        {
            x2 = (float)(cos(Stencil[i]*M_PI_8)*0.45);
            y2 = (float)(sin(Stencil[i]*M_PI_8)*0.45);
            x1 = -x2;
            y1 = -y2;
            /* Draw a line from (x + x1 + 0.5, y1 + (Height - y - 0.5))
               to (x + x2 + 0.5, y2 + (Height - y - 0.5)) */
            fprintf(File, "%.2f %.2f %.2f %.2f m1\n",
                x2 - x1, y2 - y1,
                x + x1 + 0.5f, y1 + (Height - y - 0.5f));
        }
    
    /* Finish writing the EPS file */
    if(!PsClose(File))
        goto Catch;
        
    Success = 1;
Catch:
    Free(ImageU8);
    Free(Stencil);
    Free(Mosaic);
    return Success;
}