uses
Jpeg, ClipBrd;

procedure TfrmMain.ConvertBMP2JPEG;
// converts a bitmap, the graphic of a TChart for example, to a jpeg
var
jpgImg: TJPEGImage;
begin
// copy bitmap to clipboard
chrtOutputSingle.CopyToClipboardBitmap;
// get clipboard and load it to Image1
Image1.Picture.Bitmap.LoadFromClipboardFormat(cf_BitMap,
ClipBoard.GetAsHandle(cf_Bitmap), 0);
// create the jpeg-graphic
jpgImg := TJPEGImage.Create;
// assign the bitmap to the jpeg, this converts the bitmap
jpgImg.Assign(Image1.Picture.Bitmap);
// and save it to file
jpgImg.SaveToFile(’TChartExample.jpg’);
end;