Nec Corporation

Kohji Numata

Hiroyuki Ishikawa

Image data is sequentially read out in units of frames from a storage apparatus storing NTSC images, divided into even and odd fields for each frame, and stored into a frame buffer. A judgment is made as to whether the even field of the currently read-out frame is the same image as the even field of the immediately previous frame, and if the images are the same image data is read out without a judgment being made for 4 frames starting from the next frame and 1 frame is removed so as to form a frame from the odd field of the currently read-out frame and the even field of the next read-out frame, a non-interlaced display being made at an interval of 1/24 for 4 the next 4 four frames that include this frame.

Method for moving image playback and apparatus therefor

An image synthesizing system is provided that can prevent image deterioration resulting from synthesis applied to a predictive image to be used for the next frame. The image synthesizing system decodes and synthesizes a main frame and a sub-image compressed in different modes. The image synthesizing system includes a main image frame buffer , an alpha blending section , and an image synthesis and display . The main image frame buffer stores a main image to be referred to in the next frame decoding process. The alpha blending section alpha-blends a main image from the main image frame buffer with a decoded sub-image to produce a translucent composite image. The image synthesis and display superimposes the translucent composite image on the main image.

System and method for synthesizing images

An image synthesis system which makes it possible to refer to a decompressed image that has been stored in an image-data buffer as an image for predicting a succeeding frame at the time of MPEG decoding combines main image data that has been compressed by the MPEG method and subordinate image data that has been compressed by a method different from the MPEG method. The system includes a motion compensation processor for decompressing, on a per-macroblock basis, I-, P- and B-pictures of the main image data, which has first been subjected to inverse quantization and inverse DCT processing; a macroblock storage unit for storing a macroblock of the I-picture; and a subordinate-image macroblock generator for converting the subordinate image data to an MPEG macroblock, translucently combining data of a macroblock having a portion which overlaps the subordinate image and data of a macroblock that has been stored in the macrob lock storage unit, and creating data of the translucently combined macroblocks as a macroblock of the B-picture, which is decompressed by the motion compensation processor.

Image synthesis system and method

A picture size conversion method (and device) is provided to avoid deterioration of picture display quality such as a blur and distortion, especially with respect to motion pictures which are displayed in accordance with an interlaced display method. Herein, a size conversion table storing display flags is created in accordance with a reduction ratio, wherein each of the display flags represents a decision whether to allow display with respect to each of horizontal lines. At first, the method discriminates whether the reduction ratio (R) belongs to a first range (0<R<&frac12;) or a second range (&frac12;&lE;R<1), while the method also discriminates whether each of horizontal lines belongs to an even-numbered field or an odd-numbered field within one frame. In the case of the first range of the reduction ratio, the method thins out all of horizontal lines belonging to the even-numbered field while selectively thinning out horizontal lines belonging to the odd-numbered field with reference to the size conversion table. In the case of the second range of the reduction ratio, the method does not at all thin out the horizontal lines of the even-numbered field while selectively thinning out the horizontal lines of the odd-numbered field with reference to the size conversion table. Thus, original pictures can be converted (or reduced) in sizes in different ways in response to the first range and second range of the reduction ratio respectively.

Picture size conversion method and device thereof

Apparatus for converting color signals

In an image converting apparatus for converting image data of a field format in which a frame consists of a first field and a second field into image data of a resultant frame with a predetermined size. The apparatus includes an even-numbered field decoder for decoding each line of scanning line data of the even-numbered field, an odd-numbered field decoder for decoding scanning line data of the even-numbered field by thinning out every second line, and an original image frame buffer for combining the decoded image data with each other into one frame of image data and for storing the resultant data therein.

Image size conversion interlaced for image data

The invention provides a picture data decompression apparatus which reduces the time required for decompression of picture data and operates at a high speed. The picture data decompression apparatus includes a module switching section for extracting code patterns in units of n bits the compressed picture data, m decoding and dequantization modules, and an inverse orthogonal transform section for inverse orthogonal transforming decoded and dequantized data from the m decoding and dequantization means. Each of the decoding and dequantization modules decodes and dequantizes, from a code pattern in units of n bits extracted by the module switching section, only a predetermined variable length code of a single unique code pattern of n bits from among m different predetermined patterns. Each of the decoding and dequantization modules performs storage into the dequantized data buffer in order of coded coefficients without performing scanning conversion, and the inverse orthogonal transform section reads out the stored data of the dequantized data buffer designating an address and performs inverse orthogonal transform processing of the thus read out data.

Picture data decompression apparatus

A picture synthesizing system includes a main picture decoding section, sub-picture decoding section, color table conversion section, sub-picture data conversion section, and picture synthesizing section. The main picture decoding section decodes main picture data by a first picture compression scheme. The sub-picture decoding section outputs a color table and frame data by decoding sub-picture data by a second picture compression scheme. The color table conversion section converts the color table from the sub-picture decoding section on the basis of a display format in which a synthesized picture is displayed. The sub-picture data conversion section converts the frame data from the sub-picture decoding section. The picture synthesizing section generates sub-picture data first on the basis of the color table and frame data output from the color table conversion section and sub-picture data conversion section, and then synthesizes the sub-picture data with the main picture data output from the main picture decoding section.

Picture synthesizing system includes a color table conversion section

An apparatus which converts R, G, B color signals into Y, Cr, Cb signals and reconverts them into R, G, B signals, compensates converted Y signals in order to confine each component of R, G, B color signals to be reconverted in a dynamic range allowable for them. It is not necessary to provide time consuming processes for checking and compensating reconverted R, G, B color signals and total time required for reconversion is reduced.

In a data-compression of a moving picture employing MPEG system, the quantization step used for quantizing coefficients of frequency components obtained in DCT (discrete cosine transform), is determined on a first frame of the moving picture, and is used for all the frames of the moving picture. A frame is processed by first run of data-compression. Code volume is allotted for each block in accordance with data obtained by the first run of data-compression, and in second run of data-compression, Huffman coding is discontinued when generated code volume of a block becomes larger than the code volume allotted to the block. When generated code volume of a frame is smaller than the target code volume of a frame, the surplus target code volume is added to a target code volume of a succeeding frame.

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Tokyo, Japan

Kohji Numata