贵腐葡萄酒怎么喝:用什么语句和算法能实现图形的缩放？

我给你个缩放函数,缩放一张图片2倍耗时 13ms，希望对你有帮助,我word编辑的，到baidu里排版有点乱了,不过程序正确，你要看不清,发消息给我你的email,我给你发个word版排好的源代码

const int __idecimal = 4096;inline int AverageResize32VergeLine(BYTE * p_out,BYTE * p_in1,BYTE * p_in2,int x_verge,int x_in2,int x_delta){ //ebx : x_in2 //ecx : x_out //edi : p_out //esi : p_in1 //edx : p_in2 __asm { xor ecx,ecx cmp ecx,x_verge ja __end mov edi,p_out mov esi,p_in1 mov edx,p_in2 mov ebx,x_in2__loop: mov eax,ebx shr eax,12 movd mm0,dword ptr [esi + eax * 4 + 0] movd mm3,dword ptr [edx + eax * 4 + 0] punpcklbw mm0,mm0 punpcklbw mm3,mm3 psrlw mm0,8 psrlw mm3,8 paddw mm0,mm3 psrlw mm0,1 packuswb mm0,mm0 movd dword ptr[edi + ecx * 4 + 0],mm0 add ebx,x_delta inc ecx cmp ecx,x_verge jbe __loop__end: mov x_in2,ebx } return x_in2;}void AverageResize32Line(BYTE * p_out,BYTE * p_in1,BYTE * p_in2,int x_verge,int out_width,int x_in2,int x_delta){ //ebx : x_in2 //ecx : x_out //edi : p_out //esi : p_in1 //edx : p_in2 __asm { mov ecx,x_verge cmp ecx,out_width jae __end mov edi,p_out mov esi,p_in1 mov edx,p_in2 mov ebx,x_in2__loop:#if DOUBLE_AVERAGE mov eax,ebx sub eax,x_delta shr eax,12 movd mm0,dword ptr [esi + eax * 4 + 0] movd mm1,dword ptr [edx + eax * 4 + 0] mov eax,ebx shr eax,12 movd mm2,dword ptr [esi + eax * 4 + 0] movd mm3,dword ptr [edx + eax * 4 + 0] punpcklbw mm0,mm0 punpcklbw mm1,mm1 punpcklbw mm2,mm2 punpcklbw mm3,mm3 psrlw mm0,8 psrlw mm1,8 psrlw mm2,8 psrlw mm3,8 paddw mm2,mm3 paddw mm0,mm1 paddw mm0,mm2 psrlw mm0,2 packuswb mm0,mm0#else mov eax,ebx sub eax,x_delta shr eax,12 movd mm0,dword ptr [esi + eax * 4 + 0] mov eax,ebx shr eax,12 movd mm3,dword ptr [edx + eax * 4 + 0] punpcklbw mm0,mm0 punpcklbw mm3,mm3 psrlw mm0,8 psrlw mm3,8 paddw mm0,mm3 psrlw mm0,1 packuswb mm0,mm0#endif movd dword ptr[edi + ecx * 4 + 0],mm0 add ebx,x_delta inc ecx cmp ecx,out_width jb __loop__end: }}unsigned int AverageResize32(void * out,int out_width,int out_height,int out_pitch, const void * in,int in_width,int in_height,int in_pitch){ //边界值 int y_delta = __idecimal * in_height / out_height; int x_delta = __idecimal * in_width / out_width; int y_verge = in_height / out_height / 2; int x_verge = in_width / out_width / 2; BYTE * p_out = (BYTE *)out; int y_in2 = y_delta / 2; //y边界条件 BYTE * p_in1 = (BYTE *)in; BYTE * p_in2 = (BYTE *)((int)in + in_pitch * (y_in2 / __idecimal)); for(int y_out=0; y_out<y_verge; ++y_out) { //y,x边界条件 int x_in2 = x_delta / 2; x_in2 =
AverageResize32VergeLine(p_out,p_in1,p_in2,x_verge,x_in2,x_delta); AverageResize32Line(p_out,p_in1,p_in2,x_verge,out_width,x_in2,x_delta)
p_out = (BYTE *)((int)p_out + out_pitch); y_in2 += y_delta;
p_in2 = (BYTE *)((int)p_in2 + in_pitch * (y_in2 / __idecimal));
y_in2 %= __idecimal; }
p_in1 = (BYTE *)((int)in + in_pitch * ((y_delta * y_out - y_delta / 2) / __idecimal));
p_in2 = (BYTE *)((int)in + in_pitch * ((y_delta * y_out + y_delta / 2) / __idecimal));
for(; y_out<out_height; ++y_out)
{ //x边界条件
int x_in2 = x_delta / 2;
x_in2 = AverageResize32VergeLine(p_out,p_in1,p_in2,x_verge,x_in2,x_delta); AverageResize32Line(p_out,p_in1,p_in2,x_verge,out_width,x_in2,x_delta);
p_out = (BYTE *)((int)p_out + out_pitch); y_in2 += y_delta;
p_in1 = p_in2; //p_in1 = (BYTE *)((int)p_in1 + in_pitch * (y_in2 / __idecimal)); p_in2 = (BYTE *)((int)p_in2 + in_pitch * (y_in2 / __idecimal)); y_in2 %= __idecimal; } __asm emms; return 0;}

用C++行不？

用js吧
简单