Barcode Readers using the Camera Device in Mobile Phones 指導教授：張元翔 老師 學生：吳思穎 9977003 2011/05/25 Introduction Introduction Baseband processor：works for voice digital signal processing, protocol control, power management and fundamental functions. Application processor：works for extra application such as movie codec, still photo codec and resizing, and other extra applications. Systems Systems Execute the barcode reader application Capture from embedded camera device Process the image in DSP Decode the code Display the results Algorithms Algorithms Pre-processing Corner marks detection Fourth corner estimation Inverse perspective transformation Scanning of code Algorithms Pre-processing： 1. Histogram calculation to define the threshold of blackwhite boundaries. 2. Resizing of original image to reduce the calculation costs. 3. Recognizing QR-code area, and the filtering for the area dilatation. Algorithms Corner marks detection： Algorithms Fourth corner estimation： Algorithms Inverse perspective transformation： Algorithms Implementations & Experimental Results Implementations & Experimental Results Thank you for your attention !!!