Patent Application
20070104360
1. Field of the Invention
The present invention relates to manipulating 3D images, and more particularly, to a system and method for capturing 3D face. The disclosure of the present invention can be applied to a portable hand-help device, such as, but not limited to, Digital Still Camera (DSC), Digital Video (DV), Personal Digital Assistant (PDA), mobile electronic device, 3G mobile phone, cellular phone or smart phone.
2. Description of the Prior Art
As portable electronic devices are used widely, interesting applications and games embedded in the electronic devices are getting more popular. Nowadays the portable electronic devices, such as mobile phone and PDA (personal digital assistant), are very often incorporated with a digital image capturing system. Therefore, a sort of applications not limited to the conventional photo acquisition has become more and more popular. One of those applications is to take a human face image and then to merge the face image with a 3D (3-dimension) model used for an interactive game or for a caller identification.
A method for capturing 3D face performed by the conventional system 10 is shown in
In step S14, a camera is pointed to a human object by the user. In step S16, the camera is moved to place the human face within the rough outline of the model. In step S18, a photo is taken when the human face is placed within the outline. In step S20, the photo taken is post-manipulated, such as scrolling and size changing, to best fitting the outline. However, depending on the performance of the CPU, the manipulations of the photo can not be applicable if a low performance CPU is used. In step S22, the photo region inside the outline is cropped and saved as a texture. Finally, in step S24, the texture is mapped to the 3D face model.
Nevertheless, the conventional system for acquiring 3D face has several disadvantages. First, in order to perform 3D image data manipulation, the system will require a high performance CPU which adversely increases the implementation costs and power consumptions. Second, even though a high performance CPU is exploited, it can not deplete its entire power only for the 3D application because the CPU is for general purposes and still needs to handle tasks, such as maintenance of operating system, management of file system or handshaking of communication. Consequently, a high quality 3D face capturing system can be achieved as the requirements of complexity to be limited to a level that can be performed by the conventional CPU system. Third, due to the limitations of CPU processing power in the hand-held device, the post-processing for taking the photo is limited to scrolling and size changing that can not produce a texture best match to the model outline. As a result, the texture mapping for the 3D face model can not be accurately generated and the user needs to acquire another human face photo for correcting the mapping error which results in a time-consuming process. Finally, even, the face texture mapping can be perfectly performed, due to the power computations of the general purpose CPU, the polygon rate and the displaying frame rate are both constrained; therefore, the final quality is compromised.
An objective of the present invention is to solve the above-mentioned problems and to provide a system and method for capturing 3D face that has much better quality and does not require a powerful CPU, characterized by captured images being manipulated by a 3D graphic processor.
The present invention achieves the above-indicated objective by providing a system for capturing 3D face. The system for capturing 3D face includes following elements: (1) a digital image system, for acquiring a photo; (2) a 3D graphic processor, for manipulating image data of the photo, rendering the image data to a 3D graph or storing the image data and the 3D graph; and (3) a display device, for displaying the image data or the 3D graph.
According to another aspect of the present invention, a method for capturing 3D face first selects a 3D face model for a living object. Next, a number of acquiring angles of the 3D face model are decided. Next, a rough outline of the model selected is loaded and displayed on a display. Next, a camera of a hand-held device is pointed to the living object. Next, the camera of the hand-held device is moved to place the object face within the rough outline displayed on the screen. Next, a photo of the face is taken and saved when the face is placed within the outline. Next, the photo of a first acquiring angle is loaded. Next, the photo of a first acquiring angle is displayed on the screen concurrently with a detailed 3D face model outline. Next, an interactive displacement, rotation or zoom is performed to match the face photo to the model outline. Next, the photo within the outline is cropped and saved as the texture of the current angle when matching the outline and key registration points. Finally, the 3D graphic processor maps the saved texture image(s) to the 3D face model.
The following detailed description, given by way of example and not intended to limit the invention solely to the embodiments described herein, will best be understood in conjunction with the accompanying drawings.
The present invention discloses a system and method for capturing 3D face that is applicable to a portable hand-help device, such as, but not limited to, Digital Still Camera (DSC), Digital Video (DV), Personal Digital Assistant (PDA), mobile electronic device, 3G mobile phone, cellular phone or smart phone.
The digital image system 102 is used for acquiring a photo 120. The 3D graphic processor 104 is used for manipulating image data 122 of the photo 120, rendering the image data 122 to a 3D graph 124 or storing the photo 120, the image data 122 and the 3D graph 124, as shown in
In step S110, a number of acquiring angles of the 3D face model are decided.
In step S120, as shown in
In step S130, a camera of a hand-held device is pointed to the living object.
In step S140, the camera of the hand-held device is moved to place the object face within the rough outline 32 displayed on the screen.
In step S150, a photo of the face is taken to the digital image system 102 and saved to the 3D graphic processor 104 or the storage device 108 when the face is placed within the outline.
In step S160, if more photos need to be acquired at different angles, the procedure goes back to step S120; otherwise the procedure goes to step S170.
In step S170, the photo of a first acquiring angle is loaded into the 3D graphic processor 104.
In step S180, the photo of the first acquiring angle is displayed by the display device 106 on the screen concurrently with a detailed 3D face model outline. The detailed 3D face model outline consists of a simple shape outline corresponding to the 3D face model and several registration points corresponding to the key features of the face, such as eyes, nose and mouth. An example of a detailed 3D face model outline for the 3D face model is shown in
In step S190, as shown in
In step S200, the photo within the outline is cropped and saved to the 3D graphic processor 104 or the storage device 108 as the texture of the current angle when matching the outline and key registration points.
In step S210, if there are more photos for different angles, the procedure returns to step S170; otherwise, the procedure goes to step S220.
Finally, in step S220, the 3D graphic processor 104 maps the saved texture image(s) to the 3D face model to complete the 3D face acquisition.
Compared to the conventional system and method, the present invention has several advantages. First, since a 3D graphic processor is dedicated for the 3D face capturing system, the number of polygons manipulated and the number of frame rate are dramatically higher than the conventional CPU system. As a result, the 3D face capturing system has much better quality and is applicable to wide areas. Second, as the captured images are manipulated by the 3D graphic processor, the images can be easily adjusted to match the 3D model precisely, which reduced efforts of re-acquisition of the face images normally occurred in the conventional system. Third, due to the significant processing power of the 3D graphic processor, which is not feasible for the CPUs used in the conventional hand-held device. Therefore, by using the 3D graphic processor in the 3D face capturing system, a more realistic 3D face rendering result can be achieved than that of using CPUs. Finally, since in the system of this invention the image manipulation and 3D processing tasks are performed by the 3D graphic processor, the system does not require a powerful CPU as it does in the conventional system. Consequently, implementation costs and power consumptions can be reduced.
