procedure SetLayerMask;
  var
    pold, pnew: pbyte;
    i, j: integer;
    aw, ah: integer;  // alpha width and height
    mw, mh: integer;  // mask width and height
    v: integer;
    rx, ry: double;
    zx, zy: double;
    mx, my: integer;
    mxarr: pintegerarray;
    msk_p: pbytearray;
    l0width, l0height: integer;
    rmy: integer;
    armx: pintegerarray;
    doloop: boolean;
  begin
    if layerMask = nil then
      exit;
    if layer.fCachedLayerMask<> nil then
    begin
      // cached
      oldAlpha := lBitmap.DetachAlphaChannel();
      lBitmap.ReplaceAlphaChannel(layer.fCachedLayerMask);
      newAlpha := layer.fCachedLayerMask;
    end
    else
    begin
      // check pixelformat of layer mask
      if layerMask.Bitmap.PixelFormat <> ie8g then
      begin
        layerMask.Bitmap.PixelFormat := ie8g;
        if layerMask.Bitmap.HasAlphaChannel then
          layerMask.Bitmap.RemoveAlphaChannel;  // a layer mask cannot have alpha channel
      end;

      l0width  := Layers[0].Bitmap.Width;
      l0height := Layers[0].Bitmap.Height;
      oldAlpha := lBitmap.DetachAlphaChannel();
      newAlpha := TIEBitmap.Create;
      newAlpha.Allocate(oldAlpha.Width, oldAlpha.Height, ie8g);
      lBitmap.ReplaceAlphaChannel(newAlpha);
      aw := newAlpha.Width;
      ah := newAlpha.Height;
      mw := layerMask.Bitmap.Width;
      mh := layerMask.Bitmap.Height;
      zx := (layer.Width / layer.Bitmap.Width);
      zy := (layer.Height / layer.Bitmap.Height);
      rx := (layerMask.Width / layerMask.Bitmap.Width);
      ry := (layerMask.Height / layerMask.Bitmap.Height);
      armx := nil;

      getmem(mxarr, sizeof(integer) * aw);
      for j := 0 to aw - 1 do
        mxarr[j] := round((j * zx / rx - layerMask.PosX / rx) + layer.PosX / rx);

      if fSoftCrop = iesfAlphaBlend then
      begin
        getmem(armx, sizeof(integer) * aw);
        for j := 0 to aw - 1 do
        begin
          i := round(mxarr[j] * rx) + layer.PosX;
          if (i < 0) or (i > l0width) then
            armx[j] := 0
          else
            armx[j] := - 1;
        end;
      end;

      for i := 0 to ah - 1 do
      begin
        pold := oldAlpha.Scanline[i];
        pnew := newAlpha.Scanline[i];
        my := round((i * zy / ry - layerMask.PosY / ry) + layer.PosY / ry);
        msk_p := layerMask.Bitmap.Scanline[imin(imax(0, my), layerMask.Bitmap.Height - 1)];
        doloop := true;
        if fSoftCrop = iesfAlphaBlend then
        begin
          rmy := round(my * ry) + layer.PosY;
          if (rmy < 0) or (rmy > l0height) then
          begin
            FillChar(pnew^, aw, fSoftCropValue);
            doloop := false;
          end;
        end;
        if doloop then
        begin
          for j := 0 to aw - 1 do
          begin
            if (fSoftCrop = iesfAlphaBlend) and (armx[j] = 0) then
              v := fSoftCropValue
            else
            begin
              mx := mxarr[j];
              if (my < mh) and (my >= 0) and (mx < mw) and (mx >= 0) then
                v := msk_p[mx]
              else
                v := 0;
            end;
            if pold^ < v then
              pnew^ := pold^
            else
              pnew^ := v;
            inc(pold);
            inc(pnew);
          end;
        end;
      end;
      freemem(mxarr);
      if fSoftCrop = iesfAlphaBlend then
        freemem(armx);
    end;
  end;

procedure TMainForm.iemPhotosDblClick(Sender: TObject);
var
  LL, LT, LW, LH, NewW, NewH, CurrLayer: Integer;
  FlName: string;
  ieTemp: TImageEnView;
  i: Integer;
  FileFound: Boolean;
begin

  if MainForm.ImageEnViewMain.IsEmpty then
  begin
    exit;
  end;

  if iemPhotos.SelectedImage >= 0 then
  begin
    Screen.Cursor := crHourGlass;

    if MainForm.ImageEnViewMain.CurrentLayer.Locked or
      not MainForm.ImageEnViewMain.CurrentLayer.Visible then
    begin
      ShowMessage('Please select a Valid Photo');      
      exit;
    end;

    CurrLayer := MainForm.ImageEnViewMain.LayersCurrent;
    LL := MainForm.ImageEnViewMain.CurrentLayer.PosX;
    LT := MainForm.ImageEnViewMain.CurrentLayer.PosY;
    LW := MainForm.ImageEnViewMain.CurrentLayer.Width;
    LH := MainForm.ImageEnViewMain.CurrentLayer.Height;

    // Code Added for Inserting Photos on Selected Layer
    ieTemp := TImageEnView.Create(Application);
    ieTemp.LayersAdd;
    // Auto Roted
    ieTemp.IO.Params.JPEG_EnableAdjustOrientation := True;
    // Auto RotedR
    ieTemp.IO.LoadFromFile(iemPhotos.ImageFileName[iemPhotos.SelectedImage]);

    // +++++++++++++++++++++++++++++++++++++
    if ieTemp.Layers[ieTemp.LayersCurrent].Width < LW then
    begin
      if LW > LH then
        ieTemp.Proc.Resample(LW, -1, TResampleFilter(EnlargeFilter))
      else
        ieTemp.Proc.Resample(-1, LH, TResampleFilter(EnlargeFilter));
      if EnlargeSharpenValue > 0 then
        ieTemp.Proc.Sharpen(EnlargeSharpenValue);
    end
    else
    begin
      if LW > LH then
        ieTemp.Proc.Resample(LW, -1, TResampleFilter(ReductionFilter))
      else
        ieTemp.Proc.Resample(-1, LH, TResampleFilter(ReductionFilter));
    end;

    MainForm.ImageEnViewMain.CurrentLayer.Assign(ieTemp.CurrentLayer);
    ieTemp.Free;

    // Save the file to list
    if MainForm.lstLayerFiles.Count > 0 then
    begin
      MainForm.lstLayerFiles.Items[CurrLayer] := iemPhotos.ImageFileName
        [iemPhotos.SelectedImage];
    end;

    MainForm.ImageEnViewMain.CurrentLayer.PosX := LL;
    MainForm.ImageEnViewMain.CurrentLayer.PosY := LT;

    LW := MainForm.ImageEnViewMain.CurrentLayer.Width;
    LH := MainForm.ImageEnViewMain.CurrentLayer.Height;

    MainForm.ImageEnViewMain.Update;

    RefreshControls;
    // Code to update the List Control for the selected image
    try

      FlName := ExtractFileName(iemPhotos.ImageFileName
        [iemPhotos.SelectedImage]);
      for i := 0 to lstPhotoList.Items.Count - 1 do
      begin
        if lstPhotoList.Items[i] = FlName then
        begin
          FileFound := True;
          break;
        end
        else
        begin
          FileFound := False;
        end;
      end;

      if FileFound = False then
      begin
        lstPhotoList.Items.Add(FlName);
      end;

      FlName := ExtractFilePath(iemPhotos.ImageFileName[0]);
      FlName := FlName + PhotoList;

      lstPhotoList.Items.SaveToFile(FlName);

    except
      on E: Exception do
        ShowMessage('Error while updating Photo usage in Database' + #13 +
          E.Message);
    end;

  end;

  MainForm.ImageEnViewMain.MouseInteract := [miMoveLayers, miResizeLayers];
  lblUsedPhotos.Caption := 'Unused : ' +
    IntToStr(iemPhotos.ImageCount - GetUsedPhotos(InputPath));
  Screen.Cursor := crDefault;
end;

• Run the demo.
• Open the PSD file provided.
• Click on any photo to select it (not mask).
• Now Double Click on a photo in the ImageEnMView below.