U.S. Philips Corporation

Norman D Richards

David E Penna

Jozef M Timmermans

Paul A Winser

Jos G Schepers

Harmen D Voogd

Moving output images are presented to a two dimensional display, such as a conventional television receiver (26). Three video sources are read from a compact disc, a notional front image and a notional back image being in the form of CD-I A and B planes. A notional back plane is a full frame, full video rate image, read from the disc as a coded MPEG data stream. After decoding, each pixel of each image includes depth data and opacity data. It is thus possible for an image in the notional front or notional middle plane to pass behind an object in the notional back plane. The depth and opacity data is severely compressed for the MPEG stream, by a process of quantisation and run-length encoding. The low resolution depth values for each pixel are converted to high resolution depth values via a look up table in order to further define the depth of each notional plane.

Image processing

A method of processing a first series of values representing a row of pixels of a digitized image for differentially encoding the first series of pixel values to generate a first series of codes representing a first series of differential values; expanding each code of the first series into a group of codes to form a second series of codes, each group of codes representing a plurality of differential values whose sum is the differential value represented by the corresponding code of the first series; and decoding the second series of codes to generate a second series of pixel values for display. By transmitting or recording the first series of codes and then effectively dividing each received or reproduced differential value into two or more smaller differential values, known apparatus can be made with little modification to expand each line of a received image by a factor of two or more, depending on the number of codes in each group. The extra pixel values generated will be at least approximately linearly interpolated values. This allows improved moving pictures to be reproduced from an optical disc, for example.

Method and apparatus for encoding and storing pixel values and for

A display apparatus comprises a memory (20) and a display controller (22) adapted to read lines of an image stored in the memory in accordance with a raster-scan pattern for synchronous display. Elements are provided for periodically reconfiguring the display controller (22) so as to display an image having lines comprising pixel values interpolated between the pixel values of adjacent lines of the stored image. The display apparatus may include elements (10) for reading an image from an optical disc in accordance with the Compact Disc Interactive Standard (CD-I). A method of storing an image comprises storing picture information in combination with program information defining the required periodic reconfiguration of the display controller.

Display apparatus, a method of storing an image and a storage device

A reproducing apparatus has means for reproducing for a user images and audio items stored on a record carrier (compact disc). The apparatus is controlled by a simple microcontroller running a predetermined program. To enable items to be presented to the user in a reproduction sequence with user-selected branching, the desired reproduction sequence is broken into selection points and linear reproduction sequences. A selection item is stored on the disc for each selection point, while a sequence item is stored for each linear reproduction sequence, these sequence and selection items containing further item references to link them into the described composite reproduction sequence. The logic and storage requirements imposed on the microcontroller are minimal.

Method of storing user information items and apparatus for reproducing

A method of encoding an image for CD-I players comprises obtaining the pixel information as a first matrix (M1) of 768.times.560 pixel component values, decimation filtering (1) the first matrix (M1) to produce a second matrix (M2) of 384.times.560 pixel component values, encoding (2) the second matrix (M2) to produce a first set of DYUV digital data (RDD1) for storage on a compact disc (SM), applying the digital data (RDD1) to a decoder (3) to form a third matrix (M3) of 384.times.560 pixel component values, interpolation filtering (4) the third matrix (M3) to form a fourth matrix (M4) of 768.times.560 pixel component values, forming the difference (5) between the first (M1) and fourth (M4) matrices to produce a fifth matrix (M5) of 768.times.560 difference values and encoding the fifth matrix (M5) as respective multi-bit and/or run length codes (RDD1) for storage on a compact disc (SM). Compatibility with known hardware (the CD-I standard `basecase` player) is obtained by encoding negative difference values using the quantization levels in the guard range (0-15) below black level (16, on a scale of zero to 255).

Method of encoding image pixel values for storage as compressed digital

The display apparatus includes circuitry for generating video signals for the display of still or motion pictures on a CRT or other display device. The apparatus further includes an arrangement for generating a test signal to display a test image to facilitate adjustment of the brightness (black level) setting of the CRT. The test image includes adjoining regions (100,102) of black and below-black levels, to forming a first image feature which is invisible at the correct brightness setting. If the brightness setting is too high, the first image feature is visible and forms a symbolic instruction indicating the necessary corrective adjustment. The test signal may be stored with picture information on a storage device.

Display apparatus having means for generating a test signal on the

Image data (YUVAR) are received from an image source and separated into luminance (Y) and chrominance (U,V) values. These are DPCM coded (LCO,CCO) to generate separate arrays (LAR, CAR) of delta codes. The arrays (LAR,CAR) are received in a display apparatus via a limited bandwidth data channel (120). The data channel may in particular comprise an optical disc reading device. The arrays (LAR and CAR) are then expanded and combined to generate a desired array (DAR) of standard composite code words. By coding luminance and chrominance separately, the chrominance data can be coded at low resolution relative to a display chrominance resolution so as to obtain a faster image update rate with minimal loss of perceived image quality. The expanding and combining can be performed under program control in a standard display apparatus, for example a Compact Disc-Interactive (CD-I) player.

Method of generating a series of DPCM code words, method of storing

Pixel information representing an image for display is encoded using data compression into display data which can be stored on a compact disc. The data compression consists in obtaining the pixel information as a first matrix of high resolution pixel values, subtracting from this first matrix a second matrix composed of lower resolution pixel values, produced by low pass filtering the first matrix, to produce a third matrix of difference values, decimation filtering the second matrix to produce a fourth matrix of less density lower resolution pixel values and encoding the third and fourth matrices. The complementary decoding to obtain the original data consists in restituting the second matrix by interpolation filtering the coded fourth matrix, and combining the restituted second matrix with decoded third matrix. The coding of the third matrix takes into account rate of change pixel value information obtained by delta coding the fourth matrix and the decoding of the third matrix takes into account equivalent rate of change pixel information available at the interpolation filtering.

Image encoding and decoding method and apparatus

Pixel information representing an image for display is coded using data compression. The data compression consists in obtaining the pixel information as a first matrix of high resolution pixel values, subtracting from this first matrix a second matrix composed of lower resolution pixel values, produced by low pass filtering the first matrix, to produce a third matrix of difference values, sub-sampling the second matrix to produce a fourth matrix of less density lower resolution pixel values and coding the third and fourth matrices. Complementary decoding consists in restituting the second matrix by interpolation filtering the decoded fourth matrix, and combining the restituted second matrix with the decoded third matrix. Loss of accuracy in the decoding method is reduced by coding and then decoding the fourth matrix during the coding method before it is interpolated to full pixel density to form the restituted second matrix which is subtracted from the first matrix to produce the third matrix of difference values. In this way, any sub-sampling and interpolation errors in the restituted fourth matrix occur in both the coding method and the decoding method and therefore cancel out.

Image display

Pixel information for image display is available in a mass memory as two sets of digital data of which, a first set represents values for the difference between pixel component values for an image of a given (enchanced) resolution and pixel component values for an image of lower resolution of the same pixel density, and a second set represents a lesser number of pixel component values for the lower resolution image but of reduced pixel density. In order to obtain pixel component values for displaying the enhanced resolution image, the first and second set of digital data are decoded and the pixel component values from the second set are expanded by interpolation and then added to the difference values from the first set. Different embodiments of display apparatus are described in which a display generator performs these operations in real time for a raster scan display device. This enables the two sets of digital data to be transferred from the mass memory to a display memory of the display apparatus without being recorded, thereby achieving more efficient use of the display memory. FIG. 6 gives a general layout of the display apparatus.

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Horsham, United Kingdom

Norman D Richards