Picture data compression device and red data detection device
    2.
    发明授权
    Picture data compression device and red data detection device 失效
    图像数据压缩装置和红色数据检测装置

    公开(公告)号:US06674897B1

    公开(公告)日:2004-01-06

    申请号:US08929747

    申请日:1997-09-15

    IPC分类号: G06K900

    摘要: A picture data compressing device has picture data divided by a blocking circuit 1 in to a plurality of blocks, each block consisting of a pre-set number of pixels and shuffled by a shuffling circuit 2. The blocked and shuffled data is transformed by a DCT circuit 3 into data in the frequency domain and re-quantized by a quantization circuit 4, thereby compressing the picture data. A red detector 6 determines whether a block from the shuffling circuit 2 is the red-based block. If the red detector 6 detects a red-based block, a controller 7 controls the quantization circuit 4 so that the quantization step of the quantization circuit 4 will become finer. Thus, the data of the red-based block susceptible to block distortion may be quantized with a finer quantization step for improving reproduction and alleviating block distortion.

    摘要翻译: 图像数据压缩装置具有由阻塞电路1分割成多个块的图像数据,每个块由预定数量的像素组成并由混洗电路2进行混洗。阻塞和混洗数据被DCT变换 电路3转换成频域的数据并由量化电路4重新量化,由此压缩图像数据。 红色检测器6确定来自混洗电路2的块是否是基于红色的块。 如果红色检测器6检测到基于红色的块,则控制器7控制量化电路4,使得量化电路4的量化步长变得更细。 因此,可以通过更精细的量化步长来量化易受块失真的红色块的数据,以改善再现并减轻块失真。

    Apparatus and method for producing scrambled digital video signals
    3.
    发明授权
    Apparatus and method for producing scrambled digital video signals 失效
    用于产生加扰数字视频信号的装置和方法

    公开(公告)号:US5535275A

    公开(公告)日:1996-07-09

    申请号:US263423

    申请日:1994-06-21

    摘要: Unauthorized copying of a video signal is prevented by means of a compression encoding circuit that selectively applies scrambling to the encoded signal. The compression encoding circuit is of the type which divides frames of a digital video signal into rectangular data blocks, aggregates a predetermined number of data blocks to form macroblocks, shuffles the macroblocks within the video frame, and performs discrete cosine transform processing block-by-block on the rectangular data blocks making up the shuffled macroblocks. The scrambling may be accomplished by rearranging the order of the rectangular data blocks within each macroblock, or by changing the pattern according to which macroblocks are shuffled in the video frames. The scrambling may also be accomplished by interchanging bits in a component, such as the DC component, of the DCT-processed data, or by setting such data bits to predetermined values. A compression encoding circuit with the above-described scrambling capability may be used in a digital video tape recorder (VTR), and the scrambling capability may be activated in response to a copyright protection signal present in an analog video signal supplied as an input to the digital VTR.

    摘要翻译: 通过压缩编码电路来防止视频信号的未经授权的复制,该压缩编码电路有选择地对加密信号进行加扰。 压缩编码电路是将数字视频信号的帧分割为矩形数据块的类型,聚集预定数量的数据块以形成宏块,对视频帧内的宏块进行混洗,并逐个进行离散余弦变换处理, 阻止构成洗牌宏块的矩形数据块。 可以通过重新排列每个宏块内的矩形数据块的顺序,或通过根据哪些宏块在视频帧中进行混洗来改变模式来实现加扰。 也可以通过将DCT处理的数据的诸如DC分量的分量中的比特进行交换,或者将这些数据比特设置为预定值来实现加扰。 具有上述加扰能力的压缩编码电路可以用在数字录像机(VTR)中,并且可以响应于作为输入的模拟视频信号中存在的版权保护信号来激活加扰能力 数字VTR。