Web camera

Abstract

A web camera includes an image sensor, which takes an external image; a sensor interface, which is connected to the mage sensor to receive and convert the image taken by the image sensor into digital image data; at least one compression module, which is connected to the sensor interface to receive and compress the digital image data into compressed image data; and a USB interface, which is connected to the compression module to output the compressed image data to a host device having a USB interface port, such as a computer and a USB OTG device, for storage, playing back and other applications.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In order to clearly show and make better comprehension of these and other features and advantages of the present invention, the present invention will now be described by way of examples, with reference to a preferred embodiment illustrated in the drawings, in which:

FIG. 1 shows a system block diagram of a web camera constructed in accordance with the present invention;

FIG. 2 is a block diagram of a compression module of the web camera of the present invention;

FIG. 3 shows an example format of compressed mage data supplied from the compression module of the web camera of the present invention; and

FIG. 4 is a block diagram showing an application of the web camera of the present invention.

Claims

1. A web camera, comprising: an image sensor, which is adapted to take an external image;a sensor interface, which is connected to the mage sensor to receive and convert the image taken by the image sensor into digital image data;at least one compression module, which is connected to the sensor interface to receive and compress the digital image data into compressed image data;a USB interface, which is connected to the compression module to receive and convert the compressed image data into USB image data.

2. The web camera as claimed in claim 1, wherein the image sensor comprises a CMOS image sensor.

3. The web camera as claimed in claim 1, wherein the compression module comprises: a Huffman code generator, which receives the digital image data from the sensor interface and performs Huffman compression on the digital image data to generate a Huffman code;a difference value generator, which performs operation on RGB data and gray scale data of the digital image date from the sensor interface to generates a difference value; andan operation unit, which performs operation on the Huffman code from the Huffman code generator and the difference value from the difference value generator to generate the compressed image data.

4. The web camera as claimed in claim 3, wherein the operation performed by the operation unit comprises positioning the Huffinan code from the Huffman code generator in a high byte and positioning the difference value from the difference value generator in a low byte to form unitary compressed image data.

5. The web camera as claimed in claim 1, wherein the USB interface comprises USB2.0 interface.

6. The web camera as claimed in claim 1, wherein the USB interface is mateable with a USB interface port of a host device having a USB interface port.

7. The web camera as claimed in claim 6, wherein the host device comprises a computer.

8. The web camera as claimed in claim 6, wherein the host device comprises a USB OTG device.