Abstract: A method of editing a selected area of a digital image which consists of an array of image pixels at a relatively high resolution. The method comprises: dividing the image into a series of discrete tiles at a relatively low resolution, each tile containing a plurality of the image pixels; selecting the image area for editing by generating points on a boundary line of the image area, the points being at a resolution which is higher than the resolution of the tiles; identifying boundary tiles which contain a portion of the boundary line; for each boundary tile, generating data representing a weighting which is dependent on the extent to which that boundary tile contains pixels which are within the selected area and pixels which are outside the selected area; and editing image pixels which are within the selected image area; the editing of pixels which are within a boundary tile being dependent on the weighting associated with that boundary tile.

Abstract: A method of transmitting images from a server to a client along a communications link, comprises the steps of: dividing a relatively high resolution image into a plurality of lower resolution tiles; transmitting a first image tile to a client terminal for editing; predicting at least one further image tile to be required; and transmitting the at least one predicted tile to the client terminal using unused capacity on the communications link.

Abstract: The present invention provides a digital image processing system comprising: a first workstation at which a first set of digital image data can be analysed to determine a first set of colour correction parameter data corresponding to colour corrections to be made to the first set of image data; a second workstation at which a second set of digital image data can be analysed to determine a second set of colour correction parameter data corresponding to colour corrections to be made to the second set of image data; and a digital image processing module connected to the first and second workstations so as to receive correction requests containing the first and second image data sets and first and second colour correction parameter data sets respectively from the first and second workstations, wherein the digital image processing module comprises a programmable logic device. The invention further provides a method of processing digital image data using the system of the invention.

Abstract: A system for scanning cinematographic film so as to produce digital images corresponding to the images on frames of the film is provided. The system includes means for scanning the film, means for displaying the digital images obtained by scanning the film, and image processing means. The image processing means includes means for adjusting the appearance attributes of the digital images obtained and further includes (a) means for displaying the output signal level versus time in graphical form for the images obtained, and/or (b) means for displaying the luminance, chrominance and saturation of the images obtained in graphical form on polar axes.

Abstract: The invention relates to a method of modifying the appearance attributes of digital images comprising: defining in a first channel of a colour corrector a first set of appearance attribute corrections to be applied to the images; determining a first set of appearance attribute correction parameters corresponding to the first set of appearance attribute corrections; in the first channel of the colour corrector defining at least one further set of appearance attribute corrections to be applied to the images; determining a set of appearance attribute correction parameters corresponding to the or each of the further sets of appearance attribute corrections; and combining each of the sets of appearance attribute correction parameters into a single set of appearance attribute correction parameters. The invention also relates to a method where the channel is implemented in software and to apparatus and software for carrying out the methods.

Abstract: A frequency agile voltage controlled oscillator is provided in which amplitude control is performed by digitally controlling the current supplied to the oscillator from a current source (10). The use of digital control means that phase noise performance of the oscillator is not degraded by the introduction of noise from the current source controller.

Abstract: The invention provides a method of digitally processing a sequence of video frames, in which an object is selected in a first frame; digital object data corresponding to the shape of the object is stored on a digital data storage mechanism, together with digital modification data corresponding to a desired modification of at least one appearance attribute of the object; the object is identified in a second frame of the sequence by means of the object data; and the appearance attribute of the object in the second frame is modified in accordance with the stored modification data.

Abstract: There is disclosed a method of processing digital image data, wherein cinematographic film is scanned to produce digital image data corresponding to the image(s) stored on the film; the digital image data is stored in data storage means; adjustments are made to the digital image data by a processor at the request of an operator; when an adjustment is requested by an operator the adjustment is compared to predetermined criteria; and a signal is generated if the adjustment requires the digital image data to be re-scanned from the film. There is also disclosed a method of processing digital image data, produced by scanning a plurality of frames of cinematographic film, wherein a region of a frame of digital image data is selected and that region is replaced with a computer generated image data.

Abstract: A method for the digital manipulation of a video image, in which an object is located and replaced by another object. To account for ambient lighting effects, a base set of appearance parameter values for the first object is determined, such as average values of hue, saturation and luminance. Selected regions of the object are analysed and in respect of each selected region the extent to which actual appearance parameter values deviate from the base set of apparatus parameter values is determined. The method includes storing data representation of the positions of the regions and the respective deviations from the base set of values. The first object is replaced by a second object, and the method then includes the step of applying to regions of the second object adjustments to appearance parameter values by reference to the stored data.

Abstract: A system for scanning cinematographic film so as to produce digital images corresponding to the images on frames of the film is provided. The system includes means for scanning the film, means for displaying the digital images obtained by scanning the film, and image processing means. The image processing means includes means for adjusting the appearance attributes of the digital images obtained and further includes (a) means for displaying the output signal level versus time in graphical form for the images obtained, and/or (b) means for displaying the luminance, chrominance and saturation of the images obtained in graphical form on polar axes.

Abstract: A method and apparatus for the processing of video data in which the appearance characteristics of picture elements are modified using digital apparatus such as a color processor which provides a plurality of channels having respective processing means, each channel being adapted normally to operate to process a discrete range of characteristics, wherein the method comprises the step of operating the apparatus in an alternative mode in which at least two of the channels are used to carry out identical processing steps, spatial segments of the video data being split between said at least two channels to thereby increase the speed of processing.

Abstract: A method of controlling a telecine machine to produce an exposure log of cinematographic film, comprising the steps of: using a telecine machine to generate video images from the cinematographic film, and displaying the video images on a monitor; generating timecode data for frames of the cinematographic film; generating image adjustment control data to adjust image parameters of the video images generated by the telecine machine so as to produce video images of a desired quality; using the image adjustment control data to generate exposure level information for frames of the cinematographic film; and logging in a film exposure logging system timecode data and exposure level information for frames of the cinematographic film so as to provide the exposure log. In one arrangement the cinematographic film is negative cinematographic film and the exposure log is used to generate exposure compensation printing settings for frames of the negative cinematographic film.

Abstract: A method of using telecine apparatus to scan cinematographic film made up of individual image frames. Each frame is scanned a number of times using detected light to generate corresponding image data. Each sub-scanned portion within a frame adjoins another sub-scanned portion to enable reproduction of the complete frame by piecing-together data from the sub-scanned portions to produce data corresponding to the complete frame. To help ensure that no positional anomalies are present between adjoining sub-scans, a correlation step is carried out to identify a correlated alignment in position between data corresponding to adjoining subscans. The data from the subscans used in the correlation step is then adjusted to optimize spatial alignment between the data corresponding to the sub-scans. The correlation and adjustment of the subscan data sets may be repeated so that all of the sub-scans in a frame are optimally aligned in space, enabling the sub-scans to be combined into the complete image frame.

Abstract: A data processing system comprises a magnetic or optical disc 1, a disc controller 2, and a main data processing unit 5 communicating with the controller by means on an interface 6. The controller 2 comprises an internal processing unit which receives requests from the main data processing unit 5 for data to be read from the disc 1, and controls retrieval of the data from the disc 1 and transmission of data to the main data processing unit 5 via the interface 6. The controller 2 further comprises a buffer 3 for data read from the disc 1 prior to transmission to the main data processing unit 5. The controller 2 also comprises a look-up table 4 for modifying the data read from the disc 1 in accordance with predetermined. modification criteria prior to transmission to the main data processing unit 5. The system may be used in colour processing of image data, with the disc controller providing primary colour correction.

Abstract: A method of color correcting digital video data 21 is disclosed, comprising the steps of providing a workstation 22 connected to a source 20 of digital video data, analysing video data at the workstation 22 and making decisions relating to color corrections to be applied to the video data 21, generating color correction parameter data corresponding to the decisions, transmitting the video data and the corresponding color correction parameter data 23 to a remote color processor 28 for applying color corrections to the digital video data 26, applying color corrections to the digital video data in accordance with the correction parameter data, and returning the color corrected video data 27 from the color processor 28.

Abstract: A digital video processing system for correcting video color and other attributes, such as pixel location and sharpness. The method described may be employed by a general purpose computer or a secondary digital color processor to process images from standard or high-definition telecines, or from non-real time film scanners. Only the pixels and/or regions of a video picture to be modified are processed, so that most pixels, which are unmodified, remain free from any potential corruption. Pixels to be modified are identified by means of lookup tables which can be loaded for each frame with data indicating attributes such as hue, saturation, and luminance values, or ranges which are to be present in a pixel if that pixel is to be selected for modification. The pixel's attributes are applied to each lookup table as an address.