Three-dimensional Vision Of The Virtual Brush Model Input Acquisition Method

Brush is a unique writing tool in chinese,It has high value in the history of Chinese arts and culture. As the brush has a soft nib, In the writing, we can pick up,press,pause and turn the shaft of the brush to obtain highly expressive strokes. Brush's expressive and difficult to control is any other writing tools are difficult to achieve.In numeric age, many people begin imagine to take the brush writing into digital domain, Thus,We can inherit and develop this tranditional art form. Many reasons will affect the result of brush writing,For example the amount of ink,the material of paper and etc. In writing,The writer rotate the brush,tilt the brush,move the brush quickly and pause the movement also can produce many different strokes.So in order to Digital the brush writing process,We not only need a good virtual brush model, but also we must have a good way to get a virtual brush model's input.At present,the mainly way to get virtual brush model's input is: 1, Through a pressure-sensitive pen to write in the electronic board to get.[1]This method can obtain the plane coordinates of nib and the pressure,But it only simulate a soft brush by a hard brush, There has many different between soft pen and hard pen, It's obviously not a good way to obtain the brush's move. 2, By inserting the brush into a six degrees of freedom (DOF) force feedback devices to obtain the moves.[3]This method receive user's input by inserting the brush into a six degrees of freedom (DOF) force feedback devices, and return a pressure to the user, It can obtain three-dimensional coordinates of the pen, but the bursh is inserted in the force feedback devices, The writer is not very easy to write, And force feedback devices are very expensive. 3, Through install a Ultrasound Buzze and gyroscope on a real brush, and installed three ultrasonic receiving device at the monitors to obtain.[13][14]This method get the brush's three-dimensional coordinates by receive the signal emit from the Ultrasound signal device,And get the brush's rotation info by the Gyroscope,It can get the brush's tilt,move and rotation info accurately, More over the writer use a real brush to write, for the user it is more closer to the real writing,But it's defect is that the Ultrasound signal device and Gyroscope installed in the brush is heavy,It will affect the write's writing process. Based on the above analysis,We presents a more natural and realistic virtual brush model input Acquisition method:Multi-Camera computer vision measurement method, The user using a real brush that affixed color labels writing on the real paper,There are two calibrated cameras had recorded the writing process from different position, And then split video that obtained from two camera into frame sequence,Then integrate two frame that obtained from the two frame sequence at the same time to calculate the specific point on the color lable, And through these specific points, We can calculate three-dimensional position change in brush writing process, Finaly,we can get a writing process described by a sequence of movement parameter, This writing process is the virtual brush modle's input we needed.In this paper, completed the following work:1 Defines the three-dimensional visual way to obtain a virtual brush model input. This method is based on real writing process which would allow users to more realistic approach to writing, while just affix some of labels on the brush,It is not affect the writing, Because it is a true writing, The writing will generated real strokes which is very valuable for a brush model evaluation.2, Study the algorithms, including single-frame look for signs point algorithm; The corresponding frame on different camera with same time algorithm; signs point space location reduction algorithm; motion state obtain algorithms.3, Has developed a prototype, This prototype obtain a digital files description of the process from a real brush writing process.