Handwriting Message Design And Implementation On Mobile Phone Based On JPEG Compression

This research is based on a patent that the author applied in May 2006, which named"A Hand-writing Message Handling Function". In this patent applying, hand-writing message function on a mobile phone with touch panel was introduced.MMS(Multi-media Message Service) is an important technology for mobile phone, but it is rarely used. First, people prefer to express themselves by text instead of picture. Furthermore, the editing of an MMS message is quite complex and hard to be used. Currently, the application of MMS is mostly limited on photos transferring. MMS'powerful capability has not been fully developed till now.SMS(Short Message Service) is very successful. Due to the complexity of Chinese character input method, part of users can't use SMS. Most old people have never learned PinYin and many Southern people's pronunciation is incorrect, which leads to difficulty for them to use PinYin input method. And BiHua method is usually not fit for real use and less than 10% of people are using it. The hand-writing recognition method requests users to write the characters in a formal way and only one character allowed for one time. And users should wait for the calculation of the software recognition and pick out the corrected one from many similar recommended characters. All these problems make SMS inconvenient.The hand-writing message developed in this research overcomes part of the disadvantages of SMS and MMS. Through integration of 3 important technologies, this research introduces the specific function as follows: (1) Record the touch panel writing trace into an RGB image;(2) Compress the RGB image into a JPEG image;(3) Send the hand-writing JPEG image to destination through MMS.There is no GSM feature phone in the market supports the technology of converting the touch panel trace into RGB image. It has been implemented in this research.Due to the size limitation of MMS message, JPEG compression is used to decrease the size of the hand-writing message image significantly.In order to achieve high compression rate, RGB image should be converted to YUV format firstly. The space domain YUV format will be converted to frequency domain format by DCT calculation. Then the DCT coefficients should be quantized according to the setting of the quantization table. After quantization process, the data would be handled through RLC(Run Length Coding) coding. And then the data shall go through the Huffman coding. Through large amount of testing and analyzing, the highest permitted compression rate for the specific hand-writing message should be decided, while the image quality must still be acceptable. The compression of the image data size helps to improve the speed of MMS transfer.Comparing to SMS and MMS, the hand-writing message has it's unique advantages:(1) Similar to the traditional paper letter, the receiver is able to say the sender's handwriting.(2) The contents could be text or image, whatever the sender draws on the touch panel.(3) The message editing speed is fast and flexible.(4) Easy to use for everybody.(5) The receiver can identify the identity of the sender through the handwriting. The hand-writing message function has finally been realized. Comparing to SMS and MMS, it has showed it's unique use experience and value, which is conform to the initial design goal.This function has not been revealed in the market. With the mobile phone's LCD growing to larger and larger, the value of this technology would become brighter steadily. After the further improvement of the user friendly design and functionality richness, this function could be accepted by the market and achieve great social and economical benefits.