C,32位Windows,987字节
#include <windows.h>
#define A CreateCompatibleDC(c)
#define F z=GetPixel(d,x,y);r=z;g=z>>8;b=z>>16
#define C(X,Y) (X<0||Y<0||X>=s[2]||Y>=s[3]||!GetPixel(e,X,Y))
#define D ((C(x-1,y)||C(x+1,y)||C(x,y-1)||C(x,y+1))&&!C(x,y))
#define E(X,Y) ((Z+X-Y)*(Z+X-Y)<2501)
main(int a,int*n){HDC c,d,e,f,w;int x,y,s[9],z,*o,m,t,Z;unsigned char r,g,b,R,G,B;c=GetDC(w=GetDesktopWindow());d=A;e=A;SelectObject(d,f=LoadImage(0,n[1],0,0,0,16));SelectObject(e,LoadImage(0,n[2],0,0,0,16));GetObject(f,24,s+1);o=LocalAlloc(64/*Fixed,ZeroInit*/,8*s[2]*s[3]);for(x=t=Z=s[1]=s[0]=0;x<s[2];x++)for(y=0;y<s[3];y++)if D{F;for(m=0;m<t&&o[m]!=z;m+=2);o[m]=z;o[m+1]++;t+=2*(m>=t);}for(x=y=1;x<t;x+=2)if(o[x]>o[y])y=x;z=o[y-1];R=z;G=z>>8;B=z>>16;for(x=0;x<s[2];x++)for(y=0;y<s[3];y++){F;SetPixel(c,x,s[3]-y-1,(C(x,y)||(E(r,R)&&E(g,G)&&E(b,B)))?0x232323:0x1B0DFC);}SelectObject(c,CreateFont(-(s[2]>>2),0,0,0,400,0,0,0,0,0,0,0,0,"Arial"));SetBkMode(c,1);SetTextColor(c,0xFFFFFF);DrawText(c,"-1",2,s,37);ReleaseDC(w,c);}
- 该文件以LF作为行尾保存,而不是使用CR + LF保存以保存一些字节。
- 该程序以生成编译器警告以节省更多字节的方式编写。
- 该文件可能不会编译为64位程序,因为数组“ s[]”用于执行一些隐式转换。
- 该程序拍摄两个图像(文件名通过命令行给出):
- 第一个映像(第一个命令行参数)是Windows .BMP格式的R / G / B映像。
- 第二个图像是Alpha通道(黑色表示:0%,其他颜色表示:非0%);该文件也是.BMP格式,并且必须具有相同大小或大于第一个图像
 
- 输出图像显示在屏幕的左上角
- 我无法复制那个染黄头发的男孩。黄色似乎离白色太远(> 50)!
非高尔夫版本:
#include <windows.h>
/*
 * Although this line costs us 32 bytes
 * Replacing "CreateCompatibleDC(c)" we'll
 * save 42 bytes in the golfed version later
 * so we save 10 bytes using this define!
 */
#define A CreateCompatibleDC(c)
/*
 * Macro: Get a pixel value at (x,y) to z
 * Also get r, g, b
 */
#define F z=GetPixel(d,x,y); \
    r=z; \
    g=z>>8; \
    b=z>>16
/*
 * Macro checking if a pixel is a
 * transparent colour or lies outside the
 * image
 */
#define C(X,Y) (X<0 || Y<0 || X>=s[2] || Y>=s[3] || !GetPixel(e,X,Y))
/*
 * Macro checking if a pixel at (x,y) is a border pixel
 */
#define D ((C(x-1,y) || C(x+1,y) || C(x,y-1) || C(x,y+1)) && !C(x,y))
/*
 * Macro checking if the difference between X and Y is less than 50
 * The variable "Z" must be type "int" and zero. It is used to
 * perform an implicit cast from "BYTE" to "int".
 */
#define E(X,Y) ((Z+X-Y)*(Z+X-Y)<2501)
/*
 * Note that the second argument is "char **",
 * not "int *".
 * We ignore resulting compiler warnings...
 */
main(int a, int * n)
{
    HDC c, d, e, f, w;
    int x, y, s[9], z, *o, m, t, Z;
    unsigned char r, g, b, R, G, B;
    /*
     * Get the HDC handle to the
     * screen (allowing us to create HDCs
     * for accessing bitmap files as well as
     * drawing directly to the screen!)
     */
    c=GetDC(w=GetDesktopWindow());
    /*
     * Create two virtual HDCs for accessing
     * the bitmap files.
     */
    d=A; /* Macro */
    e=A; /* Macro */
    /*
     * Load the two images:
     * The first argument is the image file with
     * the R/G/B channel
     * The second argument is the image file
     * containing the mask defined by the Alpha
     * channel:
     *   Black means = Alpha=0
     *   White means = Alpha>0
     *   (Any other colour means: Alpha>0)
     *
     * Note that "f" is of the type "HBITMAP",
     * not "HDC". We save 4 bytes in the golfed
     * version using HDC instead of HBITMAP and
     * compile the C file with compiler warnings
     * switched off!
     *
     * The second image should have the same size
     * as the first one. However it may be larger
     * than the first one. It must not be smaller!
     */
    SelectObject(d,f=LoadImage(0,n[1],0,0,0,16 /* 16=LR_LOADFROMFILE */));
    SelectObject(e,LoadImage(0,n[2],0,0,0,16));
    /*
     * Get the image information (size)
     */
    GetObject(f,24,s+1);
    /*
     * Search all background colours
     */
    o=LocalAlloc(64 /* Fixed, ZeroInit */,8*s[2]*s[3]);
    for(x=t=Z=s[1]=s[0]=0;x<s[2];x++)
        for(y=0;y<s[3];y++)
            if D
    {
        F; /* Macro */
        for(m=0;m<t && o[m]!=z;m+=2);
        o[m]=z;
        o[m+1]++;
        t+=2*(m>=t);
    }
    /*
     * Search the most common one
     */
    for(x=y=1;x<t;x+=2) if(o[x]>o[y]) y=x;
    z=o[y-1];
    R=z;
    G=z>>8;
    B=z>>16;
    /*
     * Draw the image directly to the screen
     */
    for(x=0;x<s[2];x++)
        for(y=0;y<s[3];y++)
    {
        F; /* Macro */
        /* C and E are macros: */
        SetPixel(c,x,s[3]-y-1,(C(x,y) ||
            (E(r,R) && E(g,G) && E(b,B)))?
            0x232323:0x1B0DFC);
    }
    /*
     * Draw the text over the image
     */
    SelectObject(c,CreateFont(-(s[2]>>2),0,0,0,400,0,0,0,0,0,0,0,0,"Arial"));
    SetBkMode(c,1 /* TRANSPARENT */);
    SetTextColor(c,0xFFFFFF);
    DrawText(c,"-1",2,s,37 /* center, vcenter, singleline */);
    /*
     * Unfortunately DrawText() won't work
     * when not doing this!
     */
    ReleaseDC(w,c);
}