With the availability of high-resolution cameras and increased computation power, it becomes possible to implement OCR applications such as business card readers in the mobile device. In this paper, we introduced the design and implementation of a business card reader based on a built-in camera. In order to deal with the challenge of limited resources in a mobile device, we proposed a new method based on multi-resolution analysis of document images. This method improves computation speed and reduces memory requirement of the image-processing step by detecting the text areas in the downscaled image and then analyzing each detected area in the original image. For the OCR engine, we used a two-layer classifier to improve speed. Our experiment gives a satisfactory result.