Patent Application
20110019018
1. Field of the Invention
The present invention relates generally to image processing technology, and more particularly, to an image compression system in coordination with camera motion.
2. Description of the Related Art
The data bulk of the motion pictures without any compression is very great to need very high bandwidth in file transfer and a great amount of hard drive space in storage, such that the motion pictures are usually compressed for less data bulk. Because the motion pictures are formed of consecutive images, the background of the consecutive images is nearly constant and the landscape is regularly moved. Based on such feature, an image compression manner that is so-called inter prediction coding is available.
Among the video compression standards, block motion estimation is mostly adopted for reducing temporal redundancy. Because the images at the time spot T, between T-1 and T-2, are correlative, a block at the current time spot T can be set as an unit and then the block is compared with the image between T-1 and T-2 within a set search window to locate the most similar block; next, the overlap between the two blocks is cut out to get an error block, and finally it only needs to edit the error block. Due to the analogy of the similar images, the errors converge at zero thereabouts. The more accurate the prediction concludes, the more errors approach zero. For this reason, the fewer bits need edition and thus the compression ratio is enhanced. Wherein, the vector of the motion trajectory is so-called motion vector, and the motion vector can be derived by motion estimation.
The most basic motion estimation can be carried out by a full search algorithm. Within a defined search range in a referential image, search one by one and locate the smallest block of sum of absolute difference (SAD) of the target block and then identify its motion vector. Although such algorithm has higher accuracy, the search time and the operation complexity are also increased. To lower the operation complexity, many fast algorithms are proposed, including three-step algorithm and diamond search algorithm. Since such algorithms belong to the prior art, no more description is necessary.
The primary objective of the present invention is to provide an image compression system, which can compress the images in coordination with the camera motion and eliminate the minor vibrations in the images.
The foregoing objective of the present invention is attained by the image compression system composed of a camera, a motion detection device, an image compression device, and a motion vector receiver. The motion detection device is structurally connected with the camera for detecting motions of the camera. The image compression is electrically connected with the camera for compressing motion pictures captured by the camera. The motion vector receiver is electrically connected with the motion diction device and the image compression device for receiving motion signals generated by the motions detected by the motion detection device and then transmitting the motion signals to the image compression device, whereby the image compression device can refer to the motion signals for calculation while compressing the motion pictures.
Referring to
The camera 11 is adapted for capturing motion pictures of a target scene or article.
The motion detection device 21 is structurally connected with the camera 11 for detecting motions of the camera 11. The motion detection device 21 is a gravity sensor (G-sensor), a gyroscope, a global positioning system (GPS), a radio frequency identification (RFID), a mechanical measurement device (like scale or angle gauge), or an ultrasonic positioning device.
The image compression device 31 is electrically connected with the camera 11 for compressing the motion pictures captured by the camera 11.
The motion vector receiver 41 is electrically connected with the motion detection device 21 and the image compression device 31 for receiving motion signals generated by the motions detected by the motion detection device 21 and then for transmitting the motion signals to the image compression device 31. The image compression device can refer to the motion signals for calculation while compressing the motion pictures.
The motion vector calculator 51 is electrically connected with the motion vector receiver 41 and the image compression device 31 for assisting the image compression device 31 in enhancing compression rate or decreasing the complexity of calculation of motion vector.
By reference to the data received by the motion vector receiver 41, the image compression device 31 eliminates minor vibrations in the images while compressing the same. Those minor vibrations include human body's tremors or mechanical device's trembles. The images having the minor vibrations and needing cutout are deleted and replaced by similar ones for stable motion pictures.
As shown in
How the image compression system 10 works is recited below.
When the camera 11 captures the motion pictures, the motion detection device 21 detects the motions of the camera 11 and then the motion vector receiver 41 receives the data about the motions. Next, the image compression device 31 carries out calculation of the compression of the motion pictures by reference to the data. In the meantime, the minor vibrations, like hand shaking, of the motion pictures are eliminated. Then, the motion vector calculator 51 provides the calculation of high compression rate or decreases the complexity of calculation of the motion vector.
In light of the above, in addition to enhancing the compression rate of the motion pictures, the present invention is anti-vibration to eliminate the user's natural tremors for stable motion pictures.
Referring to
The image compression system 60 further includes a motion drive device 61 and a motion control device 71. The motion drive device 61 is structurally connected with the camera 11 for driving the camera 11 to move. The motion drive device 61 is a mechanical arm, a mechanical turntable, or a self-propelled device. The motion control device 71 is electrically connected with the motion drive device 61 for controlling the motion drive device 61 and further the motions of the camera 11. The motion control device 71 is a programmable control chip in this embodiment.
The operation of the second embodiment of the present invention is similar to that of the first embodiment but different as recited thereafter. The user controls the motion drive device 61 via the motion control device 71 for motion to further drive the camera 11 to move corresponding to the motion of the camera 11 so as to comply with the requirement for motion of the camera 11 as set by the user. The motions generated by the motion drive device 61 can be converted into signals and then transmitted to the motion vector calculator 51 via the motion control device 71 or the motion detection device 21 for the basis of calculation of motion vector. The motion control device 71 can convert the motions of the camera 11 into digital or analogical signals and then transmit the signals to the motion vector calculator 51. As for other operational details, like image compression and anti-vibration, they have been disclosed in the first embodiment and thus can be omitted.
Therefore, the present invention can compress the motion pictures and meanwhile eliminate their minor vibrations by detecting the motions of the camera 11, thus having double functions of image compression and vibration reduction.
Referring to
The image compression system 80 further includes a distance meter 81 electrically connected with the motion vector calculator 51 for measuring the distance between the camera 11 and the target scene or article whose motion pictures are being captured by the camera 11. The distance meter 81 is structurally connected with the camera 11. The distance meter 81 is a secondary photographing device, a sound-ranging device, a sonar-ranging device, a radar-ranging device, an optical ranging device, or a coordinate photographing device. Among them, the sound-ranging device, the sonar-ranging device, the radar-ranging device, and the optical ranging device are well known for the person skilled in the art, such that they do not need more recitation. As for the coordinate photographing device, together with the camera 11, it can constitute 3D photograph or strengthen image quality.
Acquisition of the distance between the camera 11 and the target scene or article and calculation done by the motion vector calculator 51 can work out more accurate motion vector to assist the image compression device 31 in enhancing compression rate or image quality by reference to the information regarding the distance.
Referring to
The mage compression system 90 further includes a distance meter 81, which is identical to that of the third embodiment. The distance meter 81 of this embodiment likewise provides additional distance information to further assist the image compression device 31 in enhancing the image compression rate or the image quality. No more recitation of the distance meter 81 of this embodiment is necessary because it reaches the same effect as that of the third embodiment does.
Although the present invention has been described with respect to specific preferred embodiments thereof, it is no way limited to the details of the illustrated structures but changes and modifications may be made within the scope of the appended claims.
