Delphi影像處理 — 高保真反差

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    《Delphi影像處理》系列以效率為側重點，一般代碼為PASCAL，核心代碼採用BASM。

    《C++影像處理》系列以代碼清晰，可讀性為主，全部使用C++代碼。

    儘可能保持二者內容一致，可相互對照。

    本文代碼必須包括文章《Delphi影像處理 -- 資料類型及公用過程》中的ImageData.pas單元。

 

    映像高保真反差處理很簡單，其步驟如下：

    1、備份映像原資料；

    2、按給定半徑對映像進行高斯模糊；

    3、用原像素與高斯模糊後的像素相減，形成一個差值；

    4、差值加128，完畢。

    下面是高保真反差代碼，包括高斯模糊代碼（關於高斯模糊見文章《Delphi影像處理 -- 高斯模糊》，下面的高斯模糊代碼也是從該文拷貝來的）：

procedure CrossBlur(var Dest: TImageData; const Source: TImageData; Weights: Pointer; Radius: Integer);var  height, srcStride: Integer;  dstOffset, srcOffset: Integer;asm    push      esi    push      edi    push      ebx    push      ecx    mov       ecx, [edx].TImageData.Stride    mov       srcStride, ecx    call      _SetCopyRegs    mov       height, edx    mov       srcOffset, eax    mov       dstOffset, ebx    pop       ebx    pxor      xmm7, xmm7    push      esi           // pst = Source.Scan0    push      edi    push      edx    push      ecx    // blur col    mov       eax, srcStride    mov       edx, eax    shr       edx, 2        // width = Source.Width    mov       edi, Radius    shl       edi, 1    imul      edi, eax    add       edi, esi      // psb = pst + Radius * 2 * Source.Stride@@cyLoop:    push      edx@@cxLoop:    push      esi    push      edi    push      ebx    mov       ecx, Radius    pxor      xmm0, xmm0    // sum = 0@@cblurLoop:    movd      xmm1, [esi]   // for (i = 0; i < Radius; i ++)    movd      xmm2, [edi]   // {    punpcklbw xmm1, xmm7    punpcklbw xmm2, xmm7    paddw     xmm1, xmm2    //   ps = pst + psb    punpcklwd xmm1, xmm7    cvtdq2ps  xmm1, xmm1    //   pfs (flaot * 4) = ps (int * 4)    mulps     xmm1, [ebx]   //   pfs *= Weights[i]    addps     xmm0, xmm1    //   sum += pfs    add       ebx, 16    add       esi, eax      //   pst += Source.Stride    sub       edi, eax      //   psb -= Source.Stride    loop      @@cblurLoop   // }    movd      xmm1, [esi]    punpcklbw xmm1, xmm7    punpcklwd xmm1, xmm7    cvtdq2ps  xmm1, xmm1    // pfs (flaot * 4) = pst (int * 4)    mulps     xmm1, [ebx]   // pfs *= Weights[Radius]    addps     xmm0, xmm1    // sum += pfs    pop       ebx    pop       edi    pop       esi    cvtps2dq  xmm0, xmm0    // ps (int * 4) = sum (flaot * 4)    packssdw  xmm0, xmm7    packuswb  xmm0, xmm7    movd      [esi], xmm0   // pst (byte * 4) = ps (int * 4) pask    add       esi, 4    add       edi, 4    dec       edx    jnz       @@cxLoop    pop       edx    dec       height    jnz       @@cyLoop    pop       edx    pop       height    pop       edi           // pd = Dest.Scan0    pop       esi           // psl = pst    mov       eax, Radius    shl       eax, 1+2    add       eax, esi      // psr = psl + Radius * 2    // blur row@@ryLoop:    push      edx           // width = Dest.Width@@rxLoop:    push      esi    push      ebx    push      eax    mov       ecx, Radius    pxor      xmm0, xmm0    // sum = 0@@rblurLoop:    movd      xmm1, [esi]   // for (i = 0; i < Radius; i ++)    movd      xmm2, [eax]   // {    punpcklbw xmm1, xmm7    punpcklbw xmm2, xmm7    paddw     xmm1, xmm2    //   ps = psl + psr    punpcklwd xmm1, xmm7    cvtdq2ps  xmm1, xmm1    //   pfs (flaot * 4) = ps (int * 4)    mulps     xmm1, [ebx]   //   pfs *= Weights[i]    addps     xmm0, xmm1    //   sum += pfs    add       ebx, 16    add       esi, 4        //   psl ++    sub       eax, 4        //   psr --    loop      @@rblurLoop   // }    movd      xmm1, [esi]    punpcklbw xmm1, xmm7    punpcklwd xmm1, xmm7    cvtdq2ps  xmm1, xmm1    // pfs (flaot * 4) = psl (int * 4)    mulps     xmm1, [ebx]   // pfs *= Weights[Radius]    addps     xmm0, xmm1    // sum += pfs    cvtps2dq  xmm0, xmm0    // ps (int * 4) = sum (flaot * 4)    packssdw  xmm0, xmm7    packuswb  xmm0, xmm7    movd      [edi], xmm0   // pd (byte * 4) = ps (int * 4) pask    pop       eax    pop       ebx    pop       esi    add       eax, 4    add       esi, 4    add       edi, 4    dec       edx    jnz       @@rxLoop    add       eax, srcOffset    add       esi, srcOffset    add       edi, dstOffset    pop       edx    dec       height    jnz       @@ryLoop    pop       ebx    pop       edi    pop       esiend;// --> st x// <-- st e**x = 2**(x*log2(e))function _Expon: Extended;asm    fldl2e              // y = x*log2e    fmul    fld     st(0)       // i = round(y)    frndint    fsub    st(1), st   // f = y - i    fxch    st(1)       // z = 2**f    f2xm1    fld1    fadd    fscale              // result = z * 2**i    fstp    st(1)end;function GetWeights(var Buffer, Weights: Pointer; Q: Single; Radius: Integer): Integer;const  _fcd1: Single = 0.1;  _fc1: Single = 1.0;  _fc2: Single = 2.0;  _fc250: Single = 250.0;  _fc255: Single = 255.0;var  R: Integer;  v, QQ2: double;asm    mov     R, ecx    mov     ecx, eax    fld     Q    fabs    fcom    _fcd1    fstsw   ax    sahf    jae     @@1    fld     _fcd1    fstp    st(1)               // if (Q < 0.1) Q = 0.1    jmp     @@2@@1:    fcom    _fc250    fstsw   ax    sahf    jbe     @@2    fld     _fc250    fstp    st(1)               // if (Q > 250) Q = 250@@2:    fst     Q    fmul    Q    fmul    _fc2    fstp    QQ2                 // QQ2 = 2 * Q * Q    fwait    mov     eax, R    test    eax, eax    jg      @@10    push    eax                 // if (radius <= 0)    fld1                        // {    fadd    Q                   //   radius = Abs(Q) + 1    fistp   [esp].Integer    fwait    pop     eax@@testRadius:                   //   while (TRUE)    mov     R, eax              //   {    fldz                        //     sum = 0@@testLoop:                     //     for (R = radius; R > 0; R ++)    fild    R                   //     {    fld     st(0)    fmulp   st(1), st    fdiv    QQ2    fchs    call    _Expon              //       tmp = Exp(-(R * R) / (2.0 * Q * Q));    cmp     R, eax    jne     @@3    fst     v                   //       if (R == radius) v = tmp@@3:    faddp   st(1), st(0)        //       sum += tmp    dec     R    jnz     @@testLoop          //     }    fmul    _fc2                //     sum *= 2    fadd    _fc1                //     sum += 1    fdivr   v    fmul    _fc255    fistp   R    cmp     R, 0    je      @@4                 //     if ((INT)(v / sum * 255 + 0.5) = 0) break    inc     eax                 //     radius ++    jmp     @@testRadius        //   }@@4:    dec     eax    jnz     @@5    inc     eax@@5:    mov     R, eax              // }@@10:    inc     eax    shl     eax, 4    add     eax, 12    push    edx    push    ecx    mov     edx, eax    mov     eax, GHND    call    GlobalAllocPtr    pop     ecx    pop     edx    test    eax, eax    jz      @@Exit    mov     [ecx], eax          // buffer = GlobalAllocPtr(GHND, (Radius + 1) * 16 + 12)    add     eax, 12    and     eax, -16    mov     [edx], eax          // weights = ((char* )buffer + 12) & 0xfffffff0    mov     ecx, R              // ecx = radius    mov     edx, eax            // edx = weights    fldz                        // for (i = radius, sum = 0; i > 0; i --)@@clacLoop:                     // {    fild    R    fld     st(0)    fmulp   st(1), st    fdiv    QQ2    fchs    call    _Expon    fstp    [edx].Double        //   weights[i] = Expon(-(i * i) / (2 * Q * Q))    fadd    [edx].Double        //   sum += weights[i]    add     edx, 16    dec     R    jnz     @@clacLoop          // }    fmul    _fc2                // sum *= 2    fld1    fstp    [edx].Double        // weights[radius] = 1    fadd    [edx].Double        // sum += weights[radius]    push    ecx    inc     ecx@@divLoop:                      // for (i = 0; i <= Radius; i ++)    fld     st(0)               //   weights[i] = Round(weights[i] / sum)    fdivr   [eax].Double    fst     [eax].Single    fst     [eax+4].Single    fst     [eax+8].Single    fstp    [eax+12].Single    add     eax, 16    loop    @@divLoop    ffree   st(0)    fwait    pop     eax                 // return Radius@@Exit:end;// 高斯模糊。procedure ImageGaussiabBlur(var Data: TImageData; Q: Single; Radius: Integer);var  Buffer, Weights: Pointer;  src: TImageData;begin  Radius := GetWeights(Buffer, Weights, Q, Radius);  if Radius = 0 then Exit;  if Data.AlphaFlag then    ArgbConvertPArgb(Data);  src := _GetExpandData(Data, Radius);  CrossBlur(Data, src, Weights, Radius);  FreeImageData(src);  GlobalFreePtr(Buffer);  if Data.AlphaFlag then    PArgbConvertArgb(Data);end;procedure DoHighPass(var Dest: TImageData; const Source: TImageData);asm    push      esi    push      edi    push      ebx    pxor      mm7, mm7    mov       ecx, 128    movd      mm6, ecx    pshufw    mm6, mm6, 0    call      _SetCopyRegs@@yLoop:    push      ecx@@xLoop:    movd      mm0, [esi]  // mm0 = 原像素    movd      mm1, [edi]  // mm1 = 高斯模糊後像素    punpcklbw mm0, mm7    punpcklbw mm1, mm7    psubw     mm0, mm1    paddw     mm0, mm6    // mm0 = mm0 - mm1 + 128    packuswb  mm0, mm7    movd      [edi], mm0    add       esi, 3    add       edi, 3    movsb    loop      @@xLoop    pop       ecx    add       esi, eax    add       edi, ebx    dec       edx    jnz       @@yLoop    pop       ebx    pop       edi    pop       esi    emmsend;// 高保真反差procedure ImageHighPass(var Data: TImageData; Radius: Single);  procedure CopyData(var Dest: TImageData; const Source: TImageData);  asm    push    esi    push    edi    mov     ecx, [eax].TImageData.Width    imul    ecx, [eax].TImageData.Height    mov     edi, [eax].TImageData.Scan0    mov     esi, [edx].TImageData.Scan0    rep     movsd    pop     edi    pop     esi  end;var  IsInvertScan0: Boolean;  Src: TImageData;begin  // 備份映像資料  Src := NewImageData(Data.Width, Data.Height);  IsInvertScan0 := Data.Stride < 0;  if IsInvertScan0 then    _InvertScan0(Data);  CopyData(Src, Data);  // 映像資料作高斯模糊  ImageGaussiabBlur(Data, Radius, 0);  // 用備份映像資料和高斯模糊映像資料作高保真反差  DoHighPass(Data, Src);  FreeImageData(Src);  if IsInvertScan0 then    _InvertScan0(Data);end;

    簡單例子： 

procedure TForm1.Button2Click(Sender: TObject);var  bmp: TBitmap;  data: TImageData;begin  bmp := TBitmap.Create;  bmp.LoadFromFile('d:\source.bmp');  data := GetBitmapData(bmp);  ImageHighPass(Data, 3);  Canvas.Draw(0, 0, bmp);  bmp.Free;end;

    下面是原圖以及例子運行介面：

    《Delphi影像處理》系列使用GDI+單元和說明見文章《GDI+ for VCL基礎 -- GDI+ 與 VCL》。

    因水平有限，錯誤在所難免，歡迎指正和指導。郵箱地址：maozefa@hotmail.com

    這裡可訪問《Delphi影像處理 -- 文章索引》。