var
jpg: tjpegimage;
begin
jpg:= tjpegimage.create;
jpg.loadfromfile('*.jpg');
jpg.width:= newvalueW;
jpg.Height:= newvalueH;
jpg.savetofile('c:/1.jpg');
end;

procedure ResizeBMP(ABitMap: TBitmap; ANewWidth, ANewHeight: Integer);
var
 tmpBmp:     TBitmap;
 divHeight,
 divWidth:   double;
begin
 tmpBmp := TBitmap.Create;
 try
   tmpBmp.PixelFormat := ABitMap.PixelFormat;
   tmpBmp.Width := ABitMap.Width;
   tmpBmp.Height := ABitMap.Height;
   BitBlt(tmpBmp.Canvas.Handle, 0, 0, tmpBmp.Width, tmpBmp.Height,
          ABitMap.Canvas.Handle, 0, 0, SRCCOPY);
   divHeight := ABitMap.Height / ANewHeight;
   divWidth := ABitMap.Width / ANewWidth;
   if (divHeight = 1.0) and (divWidth = 1.0) then
   begin     //  Keine Дnderung
     ANewWidth := ABitMap.Width;
     ANewHeight := ABitMap.Height;
   end
   else if divHeight > divWidth then
   begin     //  Bei Height
     ANewWidth := trunc(ABitMap.Width / divHeight);
   end
   else      //  Bei Width
   begin
     ANewHeight := trunc(ABitMap.Height / divWidth);
   end;
   ABitMap.Width := ANewWidth;
   ABitMap.Height := ANewHeight;
   if SetStretchBltMode(ABitMap.Canvas.Handle, HALFTONE) = 0 then
   begin
     ShowMessage('SetStretchBltMode: ' + SysErrorMessage(GetLastError));
   end
   else if not SetBrushOrgEx(ABitMap.Canvas.Handle, 0, 0, nil) then
   begin
     ShowMessage('SetBrushOrgEx: ' + SysErrorMessage(GetLastError));
   end
   else if not StretchBlt(ABitMap.Canvas.Handle, 0, 0, ABitMap.Width, ABitMap.Height,
                          tmpBmp.Canvas.Handle, 0, 0, tmpBmp.Width, tmpBmp.Height, SRCCOPY) then
   begin
     ShowMessage('StretchBlt: ' + SysErrorMessage(GetLastError));
   end;
 finally
   tmpBmp.Free;
 end;
end;

Procedure ReSizeJpeg(var jpg:TJpegImage; NewWidth,NewHeight:integer);
var
 bmp,sbmp:Tbitmap;
begin
 bmp:=Tbitmap.create;
 bmp.assign(jpg);
 sbmp:=Tbitmap.create;
 sbmp.width:=NewWidth;
 sbmp.Height:=NewHeight;
 sbmp.pixelFormat:=pf24bit;
 SetStretchBltMode(sbmp.canvas.handle,4);// мягкое растягивание
 StretchBlt(sbmp.canvas.handle,0,0,NewWidth,NewHeight,bmp.canvas.handle,
               0,0,bmp.width,bmp.height,SRCCOPY);
 jpg.assign(sbmp);
 jpg.compressQuality := 90;  //существенно уменьшает размер файла, качество  на глаз не хуже
 jpg.compress;
 sbmp.free;
 bmp.free;
end;

with Image1 do
begin
 Stretch := true;
 SetBounds(Left, Top, 827, 1063);
end;

with Img1 dobegin  Stretch := true;  SetBounds(Left, Top, 827, 1063);end;

var L,R,B,T:Extended;
ax,ay:Extended
ax:=Image1.Picture.Width/Image1.Width;
ay:=Image1.Picture.Width/Image1.Height;
L:=(Image1.Left-Image1.Left);
R:=(L+Image1.Width)*ax;
B:=Image1.top*ay;
T:=B+(Image1.Height*ay));
Image1.Width:=round(R-L);
Image1.Height:=round(T-B);
Image1.Canvas.Draw(round(-L),round(-B),Image1.Picture.Graphic);

img1.Picture.Graphic:=Image1.Picture.Graphic;

procedure TForm1.Timer1Timer(Sender: TObject);
var
Srect,Drect,PosForme:TRect;
iWidth,iHeight:Integer;
iTmpX,iTmpY:Real;
C:TCanvas;

begin
 If not IsIconic(Application.Handle) then
 begin
 
  PosForme:=Rect(Form1.Left,Form1.Top,Form1.Left+Form1.Width,Form1.Top+Form1.Height);
  if not PtInRect(PosForme,Kursor) then
   begin
    if Panel1.Visible=True then Panel1.Visible:=False;
    if Image1.Visible=False then Image1.Visible:=True;
    iWidth:=Image1.Width;
    iHeight:=Image1.Height;
    Drect:=Rect(0,0,iWidth,iHeight);
    iTmpX:=iWidth / (Slider.Position * 2);
    iTmpY:=iHeight / (Slider.Position * 2);
    Srect:=Rect(Kursor.x,Kursor.y,Kursor.x,Kursor.y);
    InflateRect(Srect,Round(iTmpX),Round(iTmpY));
    // move Srect if outside visible area of the screen
    if Srect.Left<0 then OffsetRect(Srect,-Srect.Left,0);
    if Srect.Top<0 then OffsetRect(Srect,0,-Srect.Top);
    if Srect.Right>Screen.Width then OffsetRect(Srect,-(Srect.Right-Screen.Width),0);
    if Srect.Bottom>Screen.Height then OffsetRect(Srect,0,-(Srect.Bottom-Screen.Height));
    C:=TCanvas.Create;
     try
      C.Handle:=GetDC(GetDesktopWindow);
      Image1.Canvas.CopyRect(Drect,C,Srect);
     finally
      C.Free;
     end;
    //if cbSrediste.Checked=True then
    { begin // show crosshair
      with Image1.Canvas do
       begin
        DmX:=Slider.Position * 2 * (Kursor.X-Srect.Left);
        DmY:=Slider.Position * 2 * (Kursor.Y-Srect.Top);
    MoveTo(DmX - (iWidth div 4),DmY); // -
    LineTo(DmX + (iWidth div 4),DmY); // -
     MoveTo(DmX,DmY - (iHeight div 4)); // |
    LineTo(DmX,DmY + (iHeight div 4)); // |
       end; // with image1.Canvas
     end; }// show crosshair
    Application.ProcessMessages;
   end // Cursor not inside form
  else
   begin  // cursor inside form
    if Panel1.Visible=False then Panel1.Visible:=True;
    if Image1.Visible=True then Image1.Visible:=False;
   end;
end; // IsIconic
end;

procedure TForm1.btn1Click(Sender: TObject);
var L,R,B,T:Extended;
aX,aY :Extended;
begin
ax:= Image1.Picture.Width/Image1.Width;
aY:= Image1.Picture.Height/Image1.Height;
L:=(Image1.Left-Image1.Left);
R:=(L+Image1.Width)*ax;
B:=Image1.top*ay;
T:=B+(Image1.Height*ay);
Image1.Width  := round(R-L);
Image1.Height := round(T-B) ;
Image1.Canvas.Draw(round(-L), round(-B), Image1.Picture.Graphic);
 img1.Picture.Graphic:=Image1.Picture.Graphic;
 end;