C++ HLSL實(shí)現(xiàn)簡(jiǎn)單的圖像處理功能
由于對(duì)于dxva2解碼得到的數(shù)據(jù)不宜copy回內(nèi)存給CPU處理,所以最好的辦法是在GPU上直接進(jìn)行處理。D3D的像素著色器能夠?qū)ο袼刂苯舆M(jìn)行操作,實(shí)現(xiàn)點(diǎn)運(yùn)算極其簡(jiǎn)單方便,簡(jiǎn)單的卷積運(yùn)算效果也非常好。但D3D9的限制也很多,對(duì)于過于復(fù)雜的圖像處理則顯得有些不能勝任。
1.點(diǎn)運(yùn)算
點(diǎn)運(yùn)算用HLSL非常容易實(shí)現(xiàn),幾乎是公式怎么寫,代碼就怎么寫。以RGB轉(zhuǎn)灰度圖顯示為例:
texture Tex0 ;
int iFlag = 0 ;
float aValue= 0.0 ;
float bValue= 0.0 ;
sampler2D YTex =
sampler_state
{
Texture = <Tex0> ;
MipFilter = LINEAR ;
MinFilter = LINEAR ;
MagFilter = LINEAR ;
AddressU = CLAMP ;
AddressV = CLAMP ;
};
struct PS_INPUT
{
float2 uvCoords0 : TEXCOORD0 ;
};
float4 Main( PS_INPUT input ) : COLOR0
{
float4 yuvColor ;
//rgb to gray 不知道是不是這么顯示的,姑且這么認(rèn)為
float gray = tex2D( YTex, input.uvCoords0 ).r * 0.299 + tex2D( YTex, input.uvCoords0 ).g * 0.587 + tex2D( YTex, input.uvCoords0 ).b * 0.114 ;
float s = 0 ;
if(iFlag == 0)
{
s = aValue * gray + bValue/255 ;
}
else if(iFlag == 1)
{
s = aValue * log(1+gray) ;
}
else if(iFlag == 2)
{
s = aValue * pow(abs(gray),bValue) ;
}
yuvColor.r = s ;
yuvColor.g = s ;
yuvColor.b = s ;
yuvColor.a = 1.0 ;
return yuvColor ;
}
點(diǎn)運(yùn)算如此簡(jiǎn)單是因?yàn)镚PU是并行運(yùn)算的,我個(gè)人認(rèn)為可以看成是每一個(gè)像素點(diǎn)(BGRA)對(duì)應(yīng)一個(gè)線程,這大概就是OpenCL中所謂的數(shù)據(jù)并行。這是一個(gè)非常簡(jiǎn)單的程序,指令數(shù)少,程序結(jié)構(gòu)也很簡(jiǎn)單,shader 的版本用2.0就可以輕松編過。
2.卷積運(yùn)算舉例
指令數(shù)較多的情況2.0版本的shader就搞不定了,上3.0版本可以做一些簡(jiǎn)單的卷積運(yùn)算。以中值濾波為例:
texture Tex0 ;
matrix WorldMatrix;
matrix ViewMatrix;
matrix ProjMatrix;
sampler2D YTex =
sampler_state
{
Texture = <Tex0> ;
MipFilter = LINEAR ;
MinFilter = LINEAR ;
MagFilter = LINEAR ;
AddressU = CLAMP ;
AddressV = CLAMP ;
};
struct VS_INPUT
{
float4 pos : POSITION;
float4 color : COLOR0;
float2 tex : TEXCOORD0;
};
//
struct VS_OUTPUT
{
float4 pos : POSITION;
float4 color : COLOR0;
float2 tex : TEXCOORD0;
};
float2 g_v4ScreenSize;
int ksize = 1 ;
float fLeft = -1.0f ;
float fTop = -1.0f ;
float fRight = -1.0f ;
float fBottom = -1.0f ;
//--------------------------------- BurTechnique --------------------------------------
VS_OUTPUT MainVS_Screen( VS_INPUT In )
{
VS_OUTPUT Out = ( VS_OUTPUT )0;
float4x4 matWorldView = mul(WorldMatrix,ViewMatrix);
float4x4 matProject = mul(matWorldView,ProjMatrix);
Out.pos = mul(In.pos,matProject);
Out.tex = In.tex;
Out.color = In.color;
return Out;
}
float4 MainPS_Screen( VS_INPUT In ) : COLOR0
{
float4 outColor = tex2D( YTex, In.tex ).rgba ;
if(ksize <= 1 || ksize%2 == 0)
{
return outColor ;
}
if( ksize > 11 || ksize < 3)
{
return outColor ;
}
if(!(In.tex.x < fRight && In.tex.y < fBottom && In.tex.x > fLeft && In.tex.y > fTop))
{
return outColor ;
}
// 紋理大小
float2 TexSize = float2( g_v4ScreenSize.x , g_v4ScreenSize.y );
float x_off = 1.0f / TexSize.x;
float y_off = 1.0f / TexSize.y;
float2 fX0Y0 = In.tex - float2(x_off * ksize/2, y_off*ksize/2) ;
float3 sum = {0.0f, 0.0f, 0.0f} ;
if(ksize >= 3)
{
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*2)).rgb;
}
if(ksize >= 5)
{
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*4)).rgb;
}
if(ksize >= 7)
{
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*6)).rgb;
}
if(ksize >= 9)
{
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*8)).rgb;
}
if(ksize >= 11)
{
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 9, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*0)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*1)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*2)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*3)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*4)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*5)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*6)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*7)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*8)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 10, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*9)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 0, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 1, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 2, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 3, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 4, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 5, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 6, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 7, y_off*10)).rgb;
sum += tex2D( YTex , fX0Y0 + float2(x_off * 8, y_off*10)).rgb;
}
outColor = float4(sum/(ksize*ksize),1.0f);
return outColor ;
}
//--------------------------- 技術(shù)---------------------------
technique BurTechnique
{
pass P0
{
LightEnable[0] = false;
VertexShader = compile vs_3_0 MainVS_Screen();
PixelShader = compile ps_3_0 MainPS_Screen();
}
}
由于3.0版本的shader似乎不允許pixel shader單獨(dú)出現(xiàn),所以我從點(diǎn)運(yùn)算用像素著色器實(shí)現(xiàn)改為用特效來實(shí)現(xiàn)。HLSL語法中有if語句,也有for語句,可是這個(gè)程序卻不厭其煩的把所有的都給列出來來,而沒有使用for循環(huán)。這是因?yàn)樵趯?shí)際使用中發(fā)現(xiàn)有一些限制,比如if語句的if(A>B),A與B中必須有一個(gè)是常量,就像上面見到的那種形式;for循環(huán)中間的判斷也是如此,只是在第二層j循環(huán)中可以是第一層循環(huán)的i,即不可以
for(int i=0;i<ksize;i++)
{
for(int j=0;j<ksize1;j++)
{
..........
}
}
以上代碼的ksize與ksize1都必須為常數(shù),例外的情況是ksize1可以為第一層循環(huán)的 i 。這個(gè)問題不知道后續(xù)版本的shader有沒有,反正我當(dāng)前使用的版本有。
另外有一個(gè)需要注意的地方是指令數(shù),2.0版本的shader支持的指令數(shù)相當(dāng)少,3.0版本則要多好多,我最長(zhǎng)寫到了400多條快500條時(shí)才導(dǎo)致編譯失敗。 還有一個(gè)需要提醒的是3.0版本的shader只支持D3D 9.0C以后的。如果要求做更為復(fù)雜的圖像處理,可以的話建議上D3D11,compute shader雖然我沒用過,但從介紹來說,應(yīng)該可以處理一些更為復(fù)雜的圖像處理。
以上就是本文的全部?jī)?nèi)容,希望本文的內(nèi)容對(duì)大家的學(xué)習(xí)或者工作能帶來一定的幫助,同時(shí)也希望多多支持腳本之家!
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