function GetGraphicClass(const ext: String): TGraphicClass;
begin
  if ext='.bmp' then
    Result := TBitmap
  else if ext='.ico' then
    Result := TIcon
  else if (ext='.wmf') or (ext='.emf') then
    Result := TMetafile
  else if (ext='.jpg') or (ext='.jpeg') then
    Result := TJpegImage
  else if (ext='.tif') or (ext='.tiff') then
    Result := TWICImage
  else if ext='.png' then
    Result := TPngImage
  else if ext='.gif' then
    Result := TGifImage
  else
    Result := nil;
end;

function DownloadImage(const URL: String): TGraphic;
var GrClass: TGraphicClass;
    Stream: TMemoryStream;
    IdHTTP: TIdHTTP;
begin
  Result := nil;
  if Copy(LowerCase(URL), 1, 7)<>'http://' then begin
    Application.MessageBox('"http://" is required', 'Error');
    exit;
  end;
  GrClass := GetGraphicClass(LowerCase(ExtractFileExt(URL)));
  if GrClass=nil then begin
    Application.MessageBox('Unknown picture format', 'Error');
    exit;
  end;
  Stream := TMemoryStream.Create;
  try
    IdHTTP:= TIdHTTP.Create(nil);
    try
      IdHTTP.Get(URL, Stream);
    except
      Application.MessageBox('Cannot download the image', 'Error');
      FreeAndNil(Stream);
    end;
    IdHTTP.Free;
    if Stream<>nil then
      try
        Result := GrClass.Create;
        Stream.Position := 0;
        Result.LoadFromStream(Stream);
      except
        Application.MessageBox('Invalid image', 'Error');
        FreeAndNil(Result);
      end;
  finally
    Stream.Free;
  end;
end;

function DownloadUrl(AUrl: string): TBitmap;
{ Download a bitmap from a url. }
var
  iIEBitmap: TieBitmap;
begin
  iIEBitmap := TieBitmap.Create;
  try
    if iIEBitmap.LoadFromURL(AUrl, '', '', '') then
    begin
      { Resample the TIEBitmap to 50% }
      iIEBitmap.Resample(iIEBitmap.Width div 2, -1, rfNone);
      Result := TBitmap.Create;
      iIEBitmap.CopyToTBitmap(Result);
    end
    else
      MessageBox(0, 'Error downloading image.', 'Warning',
        MB_ICONWARNING or MB_OK);
  finally
    iIEBitmap.Free;
  end;
end;

procedure TForm1.DownloadClick(Sender: TObject);
{ Download a bitmap from a url and assign the bitmap to TImageEnView. }
var
  iBitmap: TBitmap;
begin
  Screen.Cursor := crHourGlass;
  try
    iBitmap := TBitmap.Create;
    try
      iBitmap := DownloadUrl(Url1.Text);
      ImageEnView1.IEBitmap.Assign(iBitmap);
      ImageEnView1.Update;
    finally
      iBitmap.Free;
    end; 
  finally
    Screen.Cursor := crDefault;
  end;
end;

function DownloadUrl2(AUrl: string): TPicture;
{ Download a TPicture from a url. }
var
  iIEBitmap: TieBitmap;
begin
  iIEBitmap := TieBitmap.Create;
  try
    { Load an image from a url }
    if iIEBitmap.LoadFromURL(AUrl, '', '', '') then
    begin
      { Resample the TIEBitmap to 50% }
      iIEBitmap.Resample(iIEBitmap.Width div 2, -1, rfNone);
      Result := TPicture.Create;
      { Copy the TIEBitmap to TBitmap }
      iIEBitmap.CopyToTBitmap(Result.Bitmap);
    end
    else
      MessageBox(0, 'Error downloading image.', 'Warning',
        MB_ICONWARNING or MB_OK);
  finally
    iIEBitmap.Free;
  end;
end;

procedure TForm1.DownloadClick(Sender: TObject);
{ Download a picture from a url and assign the bitmap to TImageEnView. }
var
  iPicture: TPicture;
begin
  Screen.Cursor := crHourGlass;
  try
    iPicture := TPicture.Create;
    try
      { Get the TPicture }
      iPicture := DownloadUrl2(Url1.Text);
      { Display the picture }
      ImageEnView1.IEBitmap.Assign(iPicture.Bitmap);
      ImageEnView1.Update;
    finally
      iPicture.Free;
    end;
  finally
    Screen.Cursor := crDefault;
  end;
end;

procedure TF_Main.RvHtmlImporter1ImageRequired2(Sender: TObject;
  const src: string; var Width, Height: Integer; var Img: TGraphic);
var bmp: TBitmap;
begin
 bmp:= TBitmap.Create;
 ImageEnIO1.LoadFromURL(src);
 ImageEnProc1.AttachedIEBitmap:=ImageEnIO1.IEBitmap;
 ImageEnProc1.Resample(300,300);
 Width:= 300;
 Height:= 300;

 bmp.Assign(ImageEnProc1.AttachedIEBitmap.VclBitmap);
 Img:= bmp;
end;

iIEBitmap.CopyToTBitmap(Result.Bitmap);

procedure TForm1.DownloadClick(Sender: TObject);
{ Download a bitmap from a url and assign the bitmap to TImageEnView. }
var
  iPicture: TPicture;
  iRGB: TRGB;
begin
  Screen.Cursor := crHourGlass;
  try
    iPicture := TPicture.Create;
    try
      { Get the TPicture }
      iPicture := DownloadUrl2(Url1.Text);
      { Display the picture }
      ImageEnView1.IEBitmap.Assign(iPicture.Bitmap);
      { Make transparent }
      iRGB := ImageEnView1.IEBitmap.Pixels[0, ImageEnView1.IEBitmap.Height - 1];
      ImageEnView1.Proc.SetTransparentColors(iRGB, iRGB, 0);
      ImageEnView1.Update;
    finally
      iPicture.Free;
    end;
  finally
    Screen.Cursor := crDefault;
  end;
end;