TIEVisionImage.matchTemplateMulti

Declaration

function matchTemplateMulti(templ: TIEVisionImage; templMask: TIEVisionImage; thresholdRank: double; out rects: TIEVisionVectorRect; out ranks: TIEVisionVectorDouble): int32_t; safecall;

Description

Search the image for the locations of the template image and returns the number of matches.

Parameter	Description
templ	Template image to find. It must be not larger than the source image
templMask	Pixels to use in template image (ie the template alpha mask). >0 use pixel (usually this is AlphaChannel)
thresholdRank	Minimum rank required. Range is 0 to 100%, though generally values of <90% are not good matches
rects	Vector (list) of rectangles representing bounding boxes of found objects
ranks	Vector (list) of doubles representing ranks found objects

Note:
◼If only a single result is required, use matchTemplate
◼For a map of comparison results, use matchTemplateAsMap
◼A shortcut method for this is available: MatchTemplate

Template Mask
It is recommended that you specify a template mask (i.e. by providing the alpha channel of the image), this prevents the background from being included in the object identification (e.g. if you pass an image with a lot of white background, it will match with any white in the image).
If your image does not have an alpha channel, you might want to remove the background using SetTransparentColors, e.g.

ImageEnMView1.GetTIEBitmap(idx).SetTransparentColors( CreateRGB(255, 255, 255), 12, 0 );
templMask := ImageEnMView1.GetTIEBitmap(idx).AlphaChannel.GetIEVisionImage(true);

Demos

	Demos\IEVision\PatternMatchingMulti\PatternMatchingMulti.dpr
	Demos\ImageEditing\EveryMethod\EveryMethod.dpr

Example

var
  image, templ, templMask: TIEVisionImage;
  rects: TIEVisionVectorRect;
  ranks: TIEVisionVectorDouble;
  i, count: Integer;
begin
  // Get image to search in (from ImageEnView1)
  image := ImageEnView1.IEBitmap.GetIEVisionImage();

  // Get the template image that we want to find (from ImageEnView2)
  templ := ImageEnView2.IEBitmap.GetIEVisionImage();

  // Get the template mask (to exclude the alpha channel)
  if ImageEnView2.IEBitmap.HasAlphaChannel() then
    templMask := ImageEnView2.IEBitmap.AlphaChannel.GetIEVisionImage(true)
  else
    templMask := nil;

  // Perform the template search
  count := image.matchTemplateMulti(templ, templMask, 95, rects, ranks);

  for i := 0 to count - 1 do
  begin
    // draw a red box around the found rectangle
    ImageEnView1.LayersAdd( ielkText, IEVisionRectToTRect( rects.getRect(i) ));
    with TIETextLayer( ImageEnView1.CurrentLayer ) do
    begin
      BorderColor := clRed;
      BorderWidth := 2;
      FillColor    := clWhite;
      Opacity      := 0.66;
      Font.Height := 24;
      Font.Color   := clRed;
      WordWrap     := False;
      Alignment    := iejCenter;
      Text         := '#' + IntToStr(i + 1) + ' ' + FloatToStr(trunc(ranks.getDouble(i))) + '%';
      TextOverflow := ieoShrink;
    end;
  end;
end;

TIEVisionImage.matchTemplateMulti