Eastman-kodak Company

Richard A Sharman

John A Weldy

Jennifer C Loveridge

Michael J Simons

Andrew Green

Philip G Powell

Peter Thomas Fry

Roger T Lees

Peter B Watt

Clare Elizabeth Scriven

A method of processing data from a digital image to optimize the tonescale to a printer being used without operator intervention adjusts the gain and offset of the input image data to occupy the full range of the printer, adjusts the shadow and highlight regions of the input image data to move that data distribution to that expected of the printer and then uses a gamma correction stage to move the mean level of the image data toward that expected for the printer.

Tone scale adjustment

A method of correcting a digital image comprises the steps of removing unrepresentative pixels, measuring the mean levels of the remaining pixels for each channel, determining an aim mean for each channel from the measured aim mean, determining a correction level, calculating a power law correction for each channel from the aim mean and the correction level and applying the power law correction to the input image to give a corrected output image.

Processing of digital images

A method of processing digital images which gradually substitutes a processed and/or filtered version of the input data for the original data. The method is applied to shadow regions of a color digital image to remove residual dark area color casts.

Correction of digital images

A color film comprises a support layer, a layer formed of a color filter array having at least three spectrally distinguishable types of color element and an emulsion layer unit. The film further includes means for emitting or reflecting light which has been modulated by the filter array but not by the image pattern formed in the emulsion layer.

Color filter array film

Described herein is a method of scanning an image formed on a color filter array film using a monochrome scanner. The image forming layer of the film is chosen so as to have a maximum density which occupies a small portion of the dynamic density range of the scanner, the excess density range of the scanner being used to decode the colors of the color filter array.

Scanning of images

Described herein is a method and apparatus for illuminating film containing emissive interlayers wherein dichroic filters are used both to determine the excitation bandwidth for the interlayers and to prevent excitation light entering a conventional color scanner.

Illumination for scanners

Described herein is a method of scanning an image by dividing the excitation and emission spectra requirements of a film (10) containing emissive interlayers (15, 16). The film (10) comprises a film base (11) on which three black-and-white records (12, 13, 14) are formed, each record being sensitive to a different color. The black-and-white records (12, 13, 14) are separated from one another by the emissive interlayers (15, 16). The emission of the interlayers and the film transmission are measured using conventional scanner color analysis.

`X` shaped filters can be used as a basis for the enhancement of images derived by electronic scanning. However, whilst such filters offer the advantage that the horizontal and vertical edges of the image will be boosted in preference to the edges at 45.degree., they are not suitable for use where a different amount of enhancement is required horizontally and vertically as is the case when scanning an anamorphic film in a telecine. Described herein is a method of image processing in which the symmetry of the detail signal obtained from the `X` filter can be modified by using a supplementary detail signal obtained from a linear filter to compensate for any asymmetry in the horizontal or vertical resolution of the original image.

Image processing to compensate for asymmetric resolution

Described herein is an arrangement for correcting the contrast of X-ray images to reveal details which are not otherwise visible. The arrangement comprises a conventional illumination box (10) for illuminating an X-ray (12), a camera arrangement (14) for viewing the illuminated X-ray film (12), the camera arrangement (14) including a camera unit (18) having a lens (20) mounted in a light tight box (16), a processing unit (22), and display means (24, 28) for displaying an image with the corrected contrast. The contrast is corrected using the characteristic curve of the processed film material on which the X-ray image is recorded in accordance with the following equation: ##EQU1## where E is the exposure,

Method for improving the contrast in photographic film materials

Identification of image-forming material type

A bandpass enhancement filter has a pass-band that tracks changes in spatial frequency due to the use of a zooming process upon a digital image signal. The primary pass-band of the enhancement filter is derived from a combination of a plurality of secondary bandpass filter sections, each having a different frequency response and each responsive to a gain adjustment. A control signal reflecting a particular zoom ratio is used in the adjustment of the gain applied to the filter sections, thereby proportioning the output of each filter section so that the combined output tracks the zooming process.

Method and apparatus for enhancing sharpness of a sequence of images

In a sampled data system with limited bandwidth where the output of a table memory 34 is multiplied with the sampled data in a multiplier 36 to produce a non-linear function, the process ordinarily produces harmonics that fold back into the passband of the system, thus causing artifacts in the processed data. By filtering the sampled data in a low pass filter 30 before addressing the table memory 34, the non-linearity of the function is progressively reduced toward the upper band limit. This reduces the production of harmonics and the resultant artifacts.

Method and apparatus for non-linear signal processing with reduced upper

A shift and add digital image processor (1) includes two sections (3) and (5), each including a latch (10, 22) for latching an input signal, an adder (18, 28) for summing two channels output from the latch with programmable delay (14, 26) therebetween, and a bit-shifting scaler (20, 30) for generating 'powers of two' functions from the output of the adder. By selecting the input to the second section (5) either from the output of the first latch (10) or from image pixels delayed by at least one line with respect to the pixels input to the first section (3), the processor may be set up to perform either one- or two-dimensional filter functions.

Shift and add digital signal processor

A motion picture film scanner generates a high definition television signal from the combination of a high definition detail component and a plurality of lower definition color components. The detail component is obtained from a luminance signal generated by a linear array sensor having a line resolution suitable for high definition scanning. The lower definition color components are obtained from three low resolution linear array sensors producing unsharp red, green and blue signals. The luminance array is divided into like-sized segments; multiple registers are then used to reach the data rate required for high definition scanning. The color photosites are large than the luminance photosites for improved signal-to-noise performance. By further selecting the number of photosites in each luminance segment to be a submultiple of the number of photosites in a color array, a common clock signal is used to read out all the linear arrays. Plural lines of luminance are thus output for each line of color, thus yielding lower color resolution in the vertical as well as the horizontal scanning direction.

Method and apparatus for generating a high definition electronic signal

An optical beam splitter is provided which removes aberrations such as coma and transverse chromatic aberration by subjecting all transmitted rays to equal and opposite amounts of induction of coma and transverse chromatic aberration, by curing residual astigmatism by providing a terminal astigmatism correcting lens in each transmitted ray path, and by avoiding ghost images by ensuring adequate separation between the main image and any ghost images. The splitter thus permits the use of high resolution, low sensitivity, linear charge coupled devices in image analysis.

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Dunstable, United Kingdom

Richard A Sharman