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While tinkering with some of the newer Apple frameworks, I ran into this very fast function in CoreImage to quickly find and scan QR codes.
Works great in Lazarus Pascal /FPC, so I though I'd share this here.
The CoreImage QR code scanner even picks up multiple QR code's in an image. And FAST.
Note that you may need to set the compiler option "-WM11.0".
Code:
I just made a simple form with a TButton, TImage, TLabel, TOpenDialog.
It allows you to select a picture and scans for QR codes right away.
The text of the QR code will be placed in the caption of Label1.
I've tested this with the latest Lazarus Pascal (trunk) but it looks like this will work in a release version as well.
unit Unit1;
{$mode objfpc}{$H+}
{$modeswitch objectivec1}
{$modeswitch objectivec2}
{$modeswitch cvar}
{$modeswitch cblocks}
{$packrecords c}
interface
uses
Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, ExtCtrls
, CocoaAll, CocoaUtils;
type
{ TForm1 }
TForm1 = class(TForm)
btnDetectQR: TButton;
Image1: TImage;
Label1: TLabel;
OpenDialog1: TOpenDialog;
procedure btnDetectQRClick(Sender: TObject);
private
public
end;
var
Form1: TForm1;
implementation
{$R *.lfm}
{ TForm1 }
procedure TForm1.btnDetectQRClick(Sender: TObject);
var
QRCodeImage : NSImage;
MyCIImage : CIImage;
Detector : CIDetector;
Features : NSArray;
Feature : CIFeature;
Filename : string;
begin
if OpenDialog1.Execute then
begin
Filename := OpenDialog1.FileName;
Image1.Picture.LoadFromFile(Filename);
QRCodeImage := NSImage.alloc.initWithContentsOfFile(NSSTR(Filename));
MyCIImage := CIImage.imageWithData(QRCodeImage.TIFFRepresentation);
Detector := CIDetector.detectorOfType_context_options(CIDetectorTypeQRCode, nil, nil);
Features := Detector.featuresInImage(MyCIImage);
label1.caption:='';
for Feature in Features do
begin
if Feature.isKindOfClass(CIQRCodeFeature) then
label1.Caption:=label1.Caption+NSStringToString(CIQRCodeFeature(Feature).messageString_)+LineEnding;
end;
end;
end;
end.
Hopefully this is useful to someone, and at the least its a nice reference for myself in case I need this in the future 😉