摘要:
The invention described here deals with implementing custom data processing of HTTPS based on a Browser-Plugin Method. Such custom data processing may include, but is not limited to, custom data compression, custom data encryption, data monitoring, data modification. There are two distinct methods to implement the Browser-Plugin Method for Advanced HTTPS Data Processing of the subject invention (BPAHDP). In both cases, BPAHDP provides the option of conducting custom data processing that co-exists with data compression, data encryption, or other types of data processing operations supported by the HTTP standard. Additionally, both BPAHDP methods ensure that the web-browser still implements and executes the underlying SSL/TLS channel setup and encryption operations. In both embodiments of BPAHDP, the most critical functionality is the ability to modify HTTP request/response headers and data sent over a TLS/SSL channel. In the regular HTTP case (HTTP over TCP) headers and data are sent as clear-text (i.e., as unencrypted data). Therefore, any HTTP proxy component can intercept and modify header/data as it chooses—allowing custom data processing operations (including a custom compression operation) to be implemented. For HTTPS traffic, the data leaving a web-browser is encrypted. Therefore, a proxy cannot modify encrypted data, hence the novelty of the BPAHDP methodology. Both methods require specific implementation methods that are described. In particular, both embodiments of BPAHDP require specific techniques to facilitate the use of Microsoft Internet Explorer as a BPAHDP enabled web-browser. Microsoft COM (Component Object Model) interfaces and IE's Pluggable Protocol capabilities are utilized to meet all requirements of both BPAHDP embodiments.
摘要翻译:这里描述的发明涉及基于浏览器插件方法实现HTTPS的定制数据处理。 这样的定制数据处理可以包括但不限于自定义数据压缩,定制数据加密,数据监视,数据修改。 实现本发明(BPAHDP)的高级HTTPS数据处理的浏览器插件方法有两种不同的方法。 在这两种情况下,BPAHDP提供了与HTTP标准支持的数据压缩,数据加密或其他类型的数据处理操作共存的自定义数据处理选项。 此外,BPAHDP方法都确保Web浏览器仍然实现和执行底层的SSL / TLS通道设置和加密操作。 在BPAHDP的两个实施例中,最关键的功能是修改HTTP请求/响应报头和通过TLS / SSL通道发送的数据的能力。 在常规HTTP情况(HTTP over TCP)中,报头和数据作为清除文本(即作为未加密数据)发送。 因此,任何HTTP代理组件都可以拦截和修改头/数据,因为它选择允许自定义数据处理操作(包括自定义压缩操作)被实现。 对于HTTPS流量,离开Web浏览器的数据将被加密。 因此,代理不能修改加密数据,因此BPAHDP方法的新颖性。 两种方法都需要具体的实现方法。 特别地,BPAHDP的两个实施例都需要特定技术来促进将Microsoft Internet Explorer用作启用BPAHDP的Web浏览器。 Microsoft COM(组件对象模型)接口和IE的可插拔协议功能被用于满足BPAHDP实施例的所有要求。
摘要:
Meta-data is generated by a client proxy based on previous response data received from a server proxy in response to a previous request for a resource. A client in communication with the client proxy makes a new request for the resource. The client proxy creates a modified request by modifying the new request to include one or more elements of the meta-data, and sends the modified request instead of the new request to the server proxy. The server proxy compares the one or more elements to corresponding one or more elements of meta-data stored in a server proxy cache. If all compared elements match, the server proxy instructs the client proxy to deliver response data stored in a client proxy cache to the client. If any of the compared elements does not match, the server proxy sends new response data to the client proxy for delivery to the client.
摘要:
A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure.
摘要:
A sequence of n coefficients is compressed by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that (i) each index in the corresponding sequence of coefficient indices is a digital number, (ii) the corresponding sequence of coefficient indices includes a plurality of values including a special value, and (iii) each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value. This involves (a) using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs; (b) applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost; and, (c) selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs; and encoding the corresponding selected cost-determined sequence of (run, index derivative) pairs using entropy coding based on a run-index derivative coding distribution.
摘要:
A system and method for caching data and verifying cached data using a client-server model and meta-data. In particular, a client proxy and a server proxy are in communication with each other and with the client and the server, respectively; client proxy meta-data and server proxy meta-data related to the data cached by the client proxy and server proxy, respectively, are calculated and communicated between the client proxy and the server proxy; and the client proxy meta-data and the server proxy meta-data are compared to determine a cache hit or miss.
摘要:
A sequence of n coefficients is compressed by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that (i) each index in the corresponding sequence of coefficient indices is a digital number, (ii) the corresponding sequence of coefficient indices includes a plurality of values including a special value, and (iii) each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value. This involves (a) using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs; (b) applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost; and, (c) selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs; and encoding the corresponding selected cost-determined sequence of (run, index derivative) pairs using entropy coding based on a run-index derivative coding distribution.
摘要:
A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure.
摘要:
A method and system for reducing the number of mathematical operations required in the JPEG decoding process without substantially impacting the quality of the image displayed is disclosed. Embodiments provide an efficient JPEG decoding process for the purposes of displaying an image on a display smaller than the source image, for example, the screen of a handheld device. According to one aspect of the invention, this is accomplished by reducing the amount of processing required for dequantization and inverse DCT (IDCT) by effectively reducing the size of the image in the quantized, DCT domain prior to dequantization and IDCT. This can be done, for example, by discarding unnecessary DCT index rows and columns prior to dequantization and IDCT. In one embodiment, columns from the right, and rows from the bottom are discarded such that only the top left portion of the block of quantized, and DCT coefficients are processed.
摘要:
A method of determining, at a mobile device, side information including compression state information. The method includes receiving, from a server, a unique side information identifier identifying a unit of side information used by the server for compressing data, determining, based on the side information identifier, if the unit of side information is resident on said device, and if the unit of side information is resident on the mobile device, loading the side information for decompressing the data. Otherwise, if the unit of side information is not resident on the mobile device, the method includes requesting the unit of side information from one of the server and another device.
摘要:
A method, system and computer software product for improving rate-distortion performance while remaining faithful to JPEG/MPEG syntax, involving joint optimization of Huffman tables, quantization step sizes and quantized coefficients of a JPEG/MPEG encoder. This involves finding the optimal coefficient indices in the form of (run, size) pairs. By employing an interative process including this search for optimal coefficient indices, joint improvement of run-length coding, Huffman coding and quantization table selection may be achieved. Additionally, the compression of quantized DC coefficients may also be improved using a trellis-structure.