JPG、PNG、GIF等图像格式转换为SVG矢量图的C代码

Convert jpeg png or gif to SVG greyscale images ImageToSVG vectorises greyscale images. It does a reasonable job on continuous tone images though a real good solution is hard. It takes the number of contours and and a contour accuracy parameter, allowing you to trade off appearance versus SVG image size.

//
//  bezierfit.c
//  ansiscratch
//
//  Created by Malcolm McLean on 13/07/2015.
//  Copyright （c） 2015 Malcolm McLean. All rights reserved.
//
#include 
#include 
#include 

#include “bezierfit.h“

typedef struct
{
    double x;
    double y;
} Point2;
typedef Point2 Vector2;

static double *g_bezier;
static int g_Nbeziers;


static void FitCurve（Point2 *d int nPts double error）;

double *bez_fitpoints（double *x double *y int N double tol int *Nbez）
{
    double *answer = 0;
    int i;
    
    g_bezier = 0;
    g_Nbeziers = 0;
    if（N == 0）
    {
        *Nbez = 0;
        return answer;
    }
    if（N == 1）
    {
        *Nbez = 1;
        
        answer = malloc（8 * sizeof（double））;
        for（i=0;i<4;i++）
        {
            answer[i/2] = x[0];
            answer[i/2+1] = y[0];
        }
        return answer;
    }
    if（N == 2）
    {
        answer = malloc（8 * sizeof（double））;
        answer[0] = x[0]; answer[1] = y[0];
        answer[2] = x[0]; answer[3] = y[0];
        answer[4] = x[1]; answer[5] = y[1];
        answer[6] = x[1]; answer[7] = y[1];
        return answer;
        
    }
    
    Point2 *pts = （Point2 *） malloc（N * sizeof（Point2））;
    for（i=0;i    {
        pts[i].x = x[i];
        pts[i].y = y[i];
    }
    FitCurve（pts N tol*tol）;
    answer = g_bezier;
	*Nbez = g_Nbeziers;
    free（pts）;
	g_bezier = 0;
	g_Nbeziers = 0;
    return answer;
out_of_memory:
    *Nbez = -1;
    return 0;
}


typedef Point2 *BezierCurve;

/* Forward declarations */
static void FitCurve（Point2 *d int nPts double error）;
static void FitCubic（Point2 *d int first int last Vector2 tHat1 Vector2 tHat2 double error）;
static BezierCurve  GenerateBezier（Point2 *d int first int last double *uPrime Vector2 tHat1 Vector2 tHat2）;
static double *Reparameterize（Point2 *d int first int last double *u BezierCurve bezCurve）;
static double NewtonRaphsonRootFind（BezierCurve Q Point2 P double u）;
static Point2 BezierII（int degree Point2 *V double t）;
static double B0（double u）;
static double B1（double u）;
static double B2（double u）;
static double B3（double u）;
static Vector2 ComputeLeftTangent（Point2 * d int end）;
static Vector2 ComputeRightTangent（Point2 * d int end）;
static Vector2 ComputeCenterTangent（Point2 *d int center）;
static double *ChordLengthParameterize（Point2 *d int first int last）;
static double ComputeMaxError（Point2 *d int first int last BezierCurve bezCurve double * u int * splitPoint）;
static Vector2 V2AddII（Vector2 a Vector2 b）;
static Vector2 V2ScaleIII（Vector2 v double s）;
static Vector2 V2SubII（Vector2 a Vector2 b）;

/*
 static	double		*Reparameterize（）;
 static	double		NewtonRaphsonRootFind（）;
 static	Point2		BezierII（）;
 static	double 		B0（） B1（） B2（） B3（）;
 static	Vector2		ComputeLeftTangent（）;
 static	Vector2		ComputeRightTangent（）;
 static	Vector2		ComputeCenterTangent（）;
 static	double		ComputeMaxError（）;
 static	double		*ChordLengthParameterize（）;
 

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2015-07-15 15:36  ImageToSVG\
     文件       21418  2015-07-14 04:26  ImageToSVG\bezierfit.c
     文件         343  2015-07-14 03:43  ImageToSVG\bezierfit.h
     文件       29994  2015-07-14 04:01  ImageToSVG\binaryutils.c
     文件        1772  2015-07-14 03:42  ImageToSVG\binaryutils.h
     文件       27219  2015-07-14 06:45  ImageToSVG\bmp.c
     文件         693  2014-12-29 17:01  ImageToSVG\bmp.h
     目录           0  2015-07-14 05:05  ImageToSVG\Debug\
     文件       40340  2015-07-14 04:26  ImageToSVG\Debug\bezierfit.obj
     文件       47233  2015-07-14 04:01  ImageToSVG\Debug\binaryutils.obj
     文件       39953  2015-07-14 05:04  ImageToSVG\Debug\bmp.obj
     文件       43397  2015-07-14 05:04  ImageToSVG\Debug\gif.obj
     文件       12351  2015-07-14 06:39  ImageToSVG\Debug\greyscaletosvg.obj
     文件        2324  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.log
     目录           0  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\
     文件        7302  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\cl.command.1.tlog
     文件       18494  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\CL.read.1.tlog
     文件       10380  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\CL.write.1.tlog
     文件         199  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\ImageToSVG.lastbuildstate
     文件        4770  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\link.command.1.tlog
     文件        6000  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\link.read.1.tlog
     文件        2434  2015-07-14 06:39  ImageToSVG\Debug\ImageToSVG.tlog\link.write.1.tlog
     文件       52992  2015-07-14 05:04  ImageToSVG\Debug\jpeg.obj
     文件       16702  2015-07-14 05:04  ImageToSVG\Debug\loadimage.obj
     文件      262459  2015-07-14 05:04  ImageToSVG\Debug\lodepng.obj
     文件        9073  2015-07-14 06:12  ImageToSVG\Debug\main.obj
     文件       21925  2015-07-14 05:05  ImageToSVG\Debug\rbtree.obj
     文件       76800  2015-07-14 06:39  ImageToSVG\Debug\vc120.idb
     文件      118784  2015-07-14 06:39  ImageToSVG\Debug\vc120.pdb
     文件       21769  2014-12-29 17:01  ImageToSVG\gif.c
     文件         295  2014-12-29 17:01  ImageToSVG\gif.h
............此处省略38个文件信息