Abstract: A photographic printer is provided including reflection densitometry apparatus for measuring the reflective density of a reflective patch or print. The apparatus includes a carrier separable from the printer for supporting a plurality of reflective patches. A light sensor is disposed on the printer, and means are disposed on the printer for supporting the carrier with a selected one of the reflective patches opposing the light sensor. Means are provided for illuminating the reflective patch, and means are provided for focusing the light reflected off of the reflective patch onto the light sensor. Further provided are means for selectively positioning at least one transmissive filter between the selected reflective patch and the light sensor.

Abstract: A photographic printer for exposing a photographic transparency onto a photosensitive medium, the photographic printer including a source of illumination for projecting light through the photographic transparency, a light sensor for sensing selected characteristics of the light projected through the photographic transparency, and a combination filter and shutter apparatus. The combination filter and shutter apparatus includes a rotatable wheel defining an exposure aperture, a calibration region for use in calibrating the light sensor, at least one opaque region of suitable size for blocking the light output of the source of illumination, and a neutral density filter region. Control means are provided for rotating the wheel to selectively position the calibration region between the source of illumination and the light sensor to enable the calibration of the light sensor.

Abstract: Three color densities of a color original are measured for a number of picture elements into which the color original is divided. A part of the color original that includes at least one picture element is selected, with whose color based on the measured densities thereof the color of each picture element based on the measured densities is compared to detect picture elements having colors identical or similar to the color of the selected part of the color original. The picture elements of the identical or similar colors can define an extent of image which determines a principal subject image and the remainder of which is background.

Abstract: A photometering method in a photographic printer where color balance and density are adjusted by a color compensation filter and where a photoprint may be made by irradiating light on an original film through a mirror box, including the steps of: setting the color compensation filter to a photometering position so as to allow the light quantity per unit area of an image information detector including an image sensor to be within a predetermined area, photometering the original film with the image information detector, and then setting the color compensation filter to an exposure position for automatic photoprinting.

Abstract: A photographic printer includes integral densitometry apparatus for performing scanned transmissive, large area transmissive, and reflective density measurements using a single light sensor. The densitometry apparatus includes a rotatable filter wheel supporting both scanning and large area transmissive filters used in making all of the density measurements. The scanning and large area density measuring apparatus use the same light projector as and share common optical hardware with that used to print pictorial negatives. The reflection densitometry apparatus includes a detachable holder for supporting reflective patches, and a second light source activated responsive to the introduction of the holder into the printer for illuminating the reflective patch.

Abstract: A transparent colored original is scanned region-by-region and the density of each region in each of the primary colors red, green and blue determined. Each region represents an area constituted by a large number of points. The densities for each region are processed to generate parameters characteristic of the coloring of the respective region. These parameters are compared with respective threshold values. An overall density for the original in each of the primary colors is now calculated. In performing these calculations, those regions for which the characteristic color parameters exceed the respective threshold values are assigned less weight than the remaining regions. This is due to the fact that the former regions are assumed to contain color dominants. The orginal is next scanned line-by-line and point-by-point in each of the primary colors to generate imaging signals for use in printing the original on copy material.

Abstract: A digital color image processing method includes generating color reproduction functions by normalizing samples of color values from the image, and processing the color components of the color digital image by applying the color reproduction functions to the respective color components of the digital image. The samples of color values are selected from the digital image by operating on a luminance component of the digital color image with an image detail detection operator to detect regions of the image representing luminance detail, and operating on the color components of the digital image in the luminance detail regions with a contrast detection filter to detect the contrast of the color components of the image in the luminance detail regions. The color values in the luminance detail regions are separated into contrast intervals and histograms in the contrast intervals are formed.

Abstract: A color image copying system (10) includes a light modulator (12) that receives incident light rays emanating from a source (14) of light. The light modulator comprises a light dispersing apparatus (54) that disperses different wavelengths of the incident light rays to different locations on a focal surface (60). A filter mask (68) aligned with the focal surface transmits preselected wavelengths of the ultraviolet light and blocks light of all other wavelengths. Each of a set of light valves (86, 88, 90) receives a different wavelength of light transmitted by the filter mask and intensity modulates it in accordance with image pixel information provided by an information source (16). An optical focusing apparatus (56) focuses the intensity-modulated wavelengths of light to a relatively small location (20) on an image focal surface (22) which is aligned with a light-sensitive medium (24).

Abstract: A problem in digital image processing employing a tone reproduction function that maximizes the quality of the processed image is to automatically determine the overall contrast of the processed image. In an improved method for determining the contrast of the processed image, the contrast is automatically determined as a function of the standard deviation of a sample of tone values used to generate the tone reproduction function by normalizing a histogram of the sample of tone values. The sample of tone values is selected from one of a plurality of samples of tone values corresponding to a plurality of contrast intervals based upon the shape of the histogram of the selected sample of tone values. To facilitate the adjustment of contrast, the tone reproduction function is constructed to produce values in units of a standard normal variate Z.

Abstract: A digital color image processing method and apparatus is characterized by producing three color reproduction functions by normalizing samples of color values from three color components of a digital image. The color reproduction functions are applied to the respective color components of the image to produce dimensionless Z values. A contrast adjusting constant is computed and the dimensionless Z values are multiplied by the constant to adjust the contrast of the processed image. Finally a constant representing the mean density for each of the color components for a particular output medium is added to the contrast adjusted Z values to produce the processed digital image.

Abstract: In a method and apparatus for determining a printing exposure amount in a photographic printing system, a characteristic value of a negative film to be printed is first obtained and an exposure amount necessary for printing the negative film is calculated from the characteristic value thereof. Information regarding a density key of the negative film is inputted in accordance with the visual discrimination of the negative film. The device for controlling the determination of the exposure amount on the basis of the density key information includes a unit for correcting the exposure amount in accordance with the density key information and a unit for classifying the inputted density key information and selecting exposure operation formulas based on the classification of the density key information so as to thereby determine a printing exposure amount. The selection of one of the abovenoted two units is done by a selecting switch as occasion demands.

Abstract: A standard exposure is established to make a desirable color print from a standard negative frame of a specific type of color original film. A negative frame of a color original film from which a color print is to be made is visually observed to judge the difference in color balance and in density from the standard frame and to determine correction values according to these differences. Upon printing, the type of the color original film is automatically detected, so as to choose automatically the appropriate one of the correction values which have been previously established according to the differences in density of various types of color original films. The frame-dependent correction values and the film-type-dependent correction value are added, so as to provide a total correction value based on which the standard exposure is corrected so as to make a fine color print from the frame.

Abstract: In conventional color photographic printers, it is emperically known that the LATD balance of RGB is substantially constant. If the exposures of three primary color components are controlled to be constant in photographic printing, standard color film negatives may be printed with excellent color balance. However, the above LATD control method is not always effective for the film negatives where a specific color is dominant, and those films are often printed with poorly balance color. The present method performs exposure control of RGB with color compensation filters controlling the color with the color compensation filter amount dependent upon factors such as the filter position, filter density, transmission factor, amount of light, etc. This method can therefore control the exposure control values at a high precision without disturbing color balance for all types of films.

Abstract: The exposure in color printers has heretofore been determined generally by LATD, but the quality of resulting prints is not always satisfactory. There have been proposed various improvements by making an operator visually inspect a negative film at a former stage of LATD measurement so as to correct the data from LATD or by scanning a frame of film for automatic judgement. They, however, are not quite satisfactory in quality, either. This invention printer allows unskilled operators to attain a high acceptance rate in printing due to the effect by an automatic judgement section as well as enables skilled operators to achieve printing at higher quality and higher acceptance rate.

Abstract: An enlarger for copying a film is provided having two modes of operation. A first mode of operation permits preliminary adjustment of the focus of the lens system while the second mode of operation permits an actual exposure, the first mode of operation being inhibited during the actual exposure of the film in the second mode.

Abstract: A strip of originals is copied onto a band of copy material at high speed using a highly automated copier which measures the densities of the originals in the primary colors and calculates exposures from the densities. The calculated exposures for each original in each primary color are recorded. The band of exposed copy material is developed and the copies are evaluated. Unsatisfactory copies are marked. The band of copy material is subsequently cut into individual copies and the unsatisfactory copies, as well as the corresponding originals, are collected. These originals are recopied in a second copier which is far less sophisticated and expensive than the first copier. The exposures used to recopy an original are derived by applying correction factors to the recorded exposures for the original. By performing the recopying procedures, which are rather slow because they require manual operations, in a second copier, the output of the high speed copier can be maintained.

Abstract: In a method of determining printing exposures, an original image to be printed is divided into at least two image extents, namely, a principal subject and a background, from each of which at least one image characteristic value is obtained based on the color densities thereof. On the basis of the obtained image characteristic values the proper exposure is determined for obtaining prints of proper densities. The proper exposure is performed by basic exposure control in which the basic exposure is obtained from the image characteristic value, or its artificially weighted value, of the principal subject image extent, and by color correction whose amount is determined either from the characteristic value of the background image extent or from the characteristic values of the both image extents.

Abstract: A color image sensor comprises a matrix of three kinds of photoelectric conversion elements for photoelectrically converting red, green, and blue color components of light, respectively, into signal charges and storing the same therein. In the matrix, the photoelectric conversion elements are grouped by m rows and n columns to form picture elements. Shift electrodes for photoelectric conversion elements corresponding to the same color are connected to one another. When a storage end signal is impressed on the shift electrodes corresponding to a selected color, the signal charges in the corresponding photoelectric conversion elements are transferred to and stored in CCDs. Color select switches are sequentially turned on so as to extract signal charges from CCDs corresponding to a selected color for each picture element in the matrix. The charges extracted from the CCDs in each picture element corresponding to the same color are simultaneously extracted and added together.

Abstract: A method of determining the color of light employed to illuminate the scene in a color image from the image itself, relies upon detecting the color of the specularly reflected light in the image. In a preferred mode of practicing the invention, the color of specularly reflected light is detected by detecting a plurality of sets of points having constant hue and varying saturation on a plurality of differently colored surfaces in the scene, and determining the locus of the intersection of straight lines fit through the color values of the sets of points. The locus of the intersection of the straight lines indicates the color of the scene illuminant. In an application of the method in a color printer, the determined illuminant color is employed as the aim point in the photographic printing process.

Abstract: This invention relates to a photographic color enlarging apparatus having a measuring device for determining the density of a test copy which, by means of the enlarging apparatus, is exposed from a reference original selected for the test-adjusting of the apparatus. Light-guiding means (15) guide light from the copying-light source of the enlarging apparatus into a measuring level outside the path of the copying rays which receives the test copies to be measured, and a photoelectric measuring sensor (25) receives measuring light reflected by the test copy. As a function of an existing density difference between the test copy and a reference copy, corrections of the exposure values are determined in such a way that a copy exposed under the new exposure conditions has the density values of the reference copy.

Abstract: An electronic printing method by which originals are photographically reproduced by exposing high-contrast copy material with an intensity modulated illumination source that coarsely scans the original while the original is sharply imaged with a well-corrected optical system. The source intensity is modulated to compensate for the original's tonal qualities and electronically shapes the response of the copy material to enhance tonal reproduction. The imaging system in conjunction with the high-contrast material assures high reproduction of detail. The method enhances copy sharpness and reduces copy time, memory and computational needs otherwise required for copies of comparable quality.

Abstract: A measuring device for selecting the color composition of the copying light when copying a film frame original in a photographic enlarging or copying apparatus has two groups of red-, green- and blue-sensitized measuring cells of which one group receives measuring light entering into the film frame original and the other group receives measuring light coming out of the film frame original. The measuring signals of each color from both groups of measuring cells are combined with one another and from the combination signals, ratios are formed of the color parts with respect to one another. As a result of the combination of measuring signals of the copying light before and after the flow through the film frame original to be copied, an undercompensation of the color deviation of individual originals with respect to a reference original is achieved.

Abstract: In a method for processing digital color images derived from photographic film, the method employing color reproduction functions generated by normalizing random samples of color values from different colors, sampling of color values from noisy areas of an image, or scanner noise can distort the randomness of sampling and result in unwanted contrast reductions and color shifts in the processed digital images. The problem is solved by correcting the shapes of the distributions of color value samples toward normal distributions having the same means and standard deviations as the sample distributions prior to forming the color reproduction functions.

Abstract: This invention relates to the printing of color photographs onto photographic paper from color negatives, and more particularly to a method and apparatus for analyzing the color correction values necessary to achieve printing of such negatives in such a way as to produce a finished print having acceptable color rendition. A method and apparatus are contemplated by which an operator may directly view a color image of a negative from which printing is to occur and directly observe the effects on printing of variations in the spectral content of light to be used for printing. By determining the specific spectral response of a lot of printing paper, a standard correction may be established which will significantly reduce the need for trial by error correction of the printing process, effecting a saving in materials and supplies as well as in time.

Abstract: Color densities of a color original are measured for a number of picture elements into which the color original is divided. A part of the color original that includes at least one picture element is selected, with whose measured color densities the measured color densities of each picture element are compared to detect picture elements of color densities having a certain relation to the color densities of the selected part of the color original. The picture elements of sufficiently similar color densities can define an extent of image which determines a principal subject image and the remainder of which is background.

Abstract: The density of an original picture film must be measured in order to determine exposure and correction amount for printing in a photographic printing system. A photosensor was heretofore arranged near an optical path of the photographic printing system and used to measure the average density of a negative film in LATD. When an original film is printed on a photographic paper, it is necessary to adjust the exposure or correction amount for various sizes of the film due to the difference in diffusion by film size. Conventionally those adjustments are performed by visually judging the size of a film and inputting the information manually via a keyboard or reading a negative size status signal of a negative carrier.

Abstract: In a photographic image information detecting method of the type in which light transmitted from an original film is received by a two-dimensional image sensor and image information is detected with respect to the divided a plurality of picture elements of the original film, a photographic image information is calibrated by the steps of detecting information of the photographic image of a reference film with respect to the original film in use of the two-dimensional image sensor, storing the thus detected information as data for calibration, and subtracting the data for calibration from the detected data regarding the image information of the original film so as to thereby obtain accurately calibrated information regarding the photographic image of the original film.

Abstract: In a method for processing digital color images derived from photographic film, the method employing color reproduction functions generated by normalizing random samples of color values from different colors, oversampling of color values from color saturated textures such as green grass and blue sky noise can distort the randomness of sampling and result in unwanted color shifts in the processed digital images. The problem is solved by constraining the shapes of and relationships between the color reproduction functions in conformance with a priori knowledge of the photographic film, and photographic conditions. According to one aspect of the invention, the shapes of the color reproduction functions are constrained in conformance with the D-Log H curves of a color photographic film. According to another aspect of the invention, the relationships between the color reproduction functions are constrained in conformance with the assumption that the illuminant employed to expose the film was a black body radiator.

Abstract: A method and apparatus for detecting and processing image information for detecting and reading out information which has been recorded on the marginal portions of a film negative sheet which are outside the image frames thereof. The marginal information is either printed or recorded on another recording medium together with the image information contained within the frames. The marginal information may be used during photographic printing so as to discriminate the front surface from the back surface thereof and/or to discriminate the top surface of the film from the bottom surface of the film.

Abstract: A color printing control system for making prints from negatives having a color printer and a microprocessor. The output of photocells which read color negatives is applied to the microprocessor enabling it to calculate print time signals. These signals are applied, for example, to paddles and move them into the light path to terminate light exposure. A print test probe reads the density of the prints and is coupled to the microprocessor and forms a feedback loop which allows the microprocessor to adjust its internal values. In this manner, color balancing is performed and prints made from over and underexposed negatives have the same density as properly exposed negatives, without knowledge of paper characteristics and without operator setup calculations.

Abstract: A problem in digital image processing is to automatically generate a tone reproduction function that maximizes the quality of the processed image. In an improved method for generating the tone reproduction function by normalizing the histogram of a sample of tone values, the sample of tone values is selected from an image dependent "floating" contrast interval using the statistical parameters of the distribution of tone values in the sample itself for the selection criteria. A plurality of histograms are formed from the tone values in a plurality of contrast intervals, and the most nearly normal histogram is selected for normalization.

Abstract: In automatic photographic printers, it is a problem to accurately detect and skip blank (unexposed or completely exposed) film frames automatically. The problem is solved by scanning a film frame in three colors to generate color value samples, compiling histograms of the color value samples, computing the standard deviations of the color histograms, comparing the standard deviations with predetermined constant values, and generating a signal indicating the presence of a blank frame when all the standard deviations are less than their respective predetermined constants. The method is particularly useful in a scanning-type color photographic printer employing histogram modification to effect tone-scale and color balance adjustments.

Abstract: In methods of digital image processing, it is a problem to automatically adjust the contrast of an image that contains a bimodal distribution of tone values, such as a back-lit scene, or some close-up flash pictures. The invention solves the problem in a digital image processing method employing a tone reproduction function generated by normalizing the histogram of a sample of tone values, by statistically testing the sample of tone values for bimodal distribution, and if the sample is determined to be bimodal, testing the statistics of the sample of tone values to determine whether the image contains useful information in the shadows, and if so, adjusting the contrast of the image by increasing the contrast of the shadow portions of the image, and decreasing the contrast of the highlight portions. A part of the sample of tone values representing the shadow portions of the image is tested for skewness, and the contrast is adjusted only if the skewness does not exceed a predetermined amount.

Abstract: In automatic color printing, there is a need to identify scenes that have been exposed with a very narrow-band illuminant and to apply no color correction to such scenes. Narrow-band illuminant scenes are identified according to the present invention by scanning the original image in three primary colors to generate three color value distributions. The statistics of the three color value distributions are computed, and if the ratio of the standard deviations for any two of the color value distributions is greater than a first predetermined constant (e.g. 4.0) or less than a second predetermined constant (e.g. 0.25), no color correction is employed. The method is particularly useful in a scanning color photographic printer employing histogram modification to effect tone-scale and color balance adjustments.

Abstract: In conventional photographic printing process, LATDs are photometrically measured for three primary colors of a color original picture to control the amount of transmitting light at a given level. Although this method of LATD control can produce excellent prints with good color balance for standard color negative films, it often produces defective prints with pool color balance for the original film frames which are dominated with specific colors. This invention method can control the color and the density optimally, remove color failures on objects, and distinguish films influenced with a color of a light source from the films with color failure to thereby provide optimum prints with minimum density fluctuation.

Abstract: In a method of digital image processing employing a tone reproduction function generated by normalizing the histogram of a sample of tone values selected from the image, it is an object to automatically detect images that were derived from over or under exposed photographic originals and to adjust the tone scale of such images to improve their appearance. The invention achieves this objective by testing the skewness of the sample of tone values of the image and if the amount of skewness exceeds a predetermined amount, adjusting the contrast of the processed image by an amount equal to the value of a standard variate computed for the sample at a mean tone value of the sample minus the value of a standard variate computed for the sample at a mode of the tone values of the sample.

Abstract: A color analyzer for determining the exposure time required for printing color photographs by an enlarger comprising a measuring unit having three photoelectric cells. The analyzer is further provided with a control unit being electrically connected to the measuring unit and having an electric circuit for determining the exposure time. According to the present invention, the characteristic values of the color components, blue, green and red are measured by a respective photoelectric cell for a test print as electric signals generated by the cells at voltages of S.sub.BO, S.sub.GO, and S.sub.RO at the associated exposure time t.sub.o. These values are stored in a memory and the exposure time t of an arbitrary picture is determined with the aid of measured signals S.sub.B, S.sub.G and S.sub.R for the components blue, green, and red. This determination is computed by way of the formula:t=3t.sub.o /[(S.sub.B /S.sub.BO)+(S.sub.G /S.sub.GO)+(S.sub.R /S.sub.RO)].

Abstract: A photographic printing apparatus for printing an image formed on a negative film on photographic paper includes a shutter disposed between the photographic paper and an enlarging lens. A reflective surface is provided on the surface of the shutter on the side thereof which is closer to the enlarging lens. A light receiver is disposed outside the optical path of exposure light in such a manner as to face the reflective surface. When the shutter is closed, the light receiver receives the light which forms an out-of-focus image at the reflective surface and is reflected therefrom. Accordingly, it is possible to measure an averaged density of the film image.

Abstract: A new method of making it possible to quickly and easily determine the optimum exposure conditions for a photographic color printer is disclosed. The method is performed by way of the steps of preparing a plurality of test prints under different exposure condition using a standard negative film, measuring optical density for each of color components on the test prints, comparing their optical density with that of corresponding color component on a standard print, detecting change in optical density per unit positional change of correction key on each of the test prints with respect to each of color components, and determining corrective value required for correcting density difference between each of test prints and standard print with reference to the above change in optical density per unit positional change of correction key.

Abstract: A laser scanning and printing apparatus operates to scan an original picture in generally low resolution to provide a minimal quantity of image data which may be modified to provide an enhanced image reproduction of the original by subsequently laser scanning the original and directing the laser light reflected from the original to expose a photosensitive material, the intensity of the laser light being modulated to effect the enhanced image reproduction by selectively lightening or darkening predetermined areas of the photosensitive material exposed by the laser light reflected from the original picture during the subsequent line scan thereof.

Abstract: A method for setting conditions in photographic printing exposure which is characterized in that an average density value U of a large number of negative films, a correction amount D.sub.1 of the light source and a correction amount D.sub.2 for the intended density are obtained, and when the density of the negative film to be printed is represented as U, the difference obtained by subtracting the density U from the sum of the average density value U and the correction amounts D.sub.1 and D.sub.2 is used as the printing condition for the negative film to be printed.

Abstract: A color printing apparatus and method in which a light chamber receives light from a light source after the light has passed through a negative supported by a negative carrier. The light chamber has a number of electronic sensors which sense the light in the chamber and control filters across the path of the light before the light strikes a color paper strip for printing the image of a negative onto the strip itself. In one embodiment of the invention, a negative carrier has a number of slots adjacent to the opening in the carrier across which the negative is to be placed in the path of the light beam. These slots provide passages for additional light from the light source into the light chamber whereby the light passing through the negative and the additional light is mixed together to dilute the total light in the chamber to normalize the readings of the sensors before the sensors are used to actuate filters across the path of the light beam.

Abstract: An enlarger having a light emitting device is provided wherein the amount and color balance of light to be emitted are controlled. The operator can set the amount and color balance of light. The enlarger can measure the amount and color balance of light at a plurality of points within a predetermined plane in which the printing paper is to be located. A first mode of operation can be set which presumes a predetermined standard film set in the enlarger and a second mode of operation can be set wherein a film to be printed is placed in the enlarger. The enlarger is capable of averaging a measured signal to determine an average amount and an average color balance of light wherein these measurements can be utilized to determine a proper amount and color balance of light to be received at the predetermined plane during an enlarging operation.

Abstract: A color printer system has a filter driver for moving a CC filter toward and away from the exposure light path, and a negative film transmission light measuring device for detecting the source light passed through the CC filter. The system is provided with control means for controlling the movement of the CC filter by controlling the filter driver such that the CC filter is moved to the following three positions: a light source target position where the source light detected by the negative film transmission light measuring device takes a predetermined quantity and a predetermined color; a photometry target position which is obtained on the basis of the light source target position; and a light adjustment target position which is obtained on the basis of the photometry target position. Accordingly, light source management, photometry and light adjustment are automatically carried out.

Abstract: A strip of exposed and developed color film is transported through a transparency measuring system. The transparency of each frame of the film strip in the three primary colors is measured at a multiplicity of regions. The transparency values are converted to density values which are processed to generate a set of data characteristic of the film strip and indicative of the color compositions of the scanned regions. The characteristic set of data and the density values for the individual regions are used to determine whether or not a respective region contains a color dominant. For each frame, the amounts of copying light in the primary colors are established from the density values of those regions which are free of color dominants and have a neutral gray color composition. The amount of copying light in each of the three primary colors is calculated so that the regions of the original having a neutral gray color composition are copied neutral gray.

Abstract: When printing a photographic film, it is necessary to determine exposure conditions by judging from the conditions of a picture image of an object. However, if the object is analyzed by photometrically measuring it at the developing stage of the negative film, it is impossible to discriminate whether the result of the analysis is attributable to the object per se or the fluctuation in film developing process. According to this invention, a film property printed portion is exposed at a predetermined location on a film beforehand for identification of the film properties, the portion being measured for the density at the time of printing, comparing the measured density with a standard value, correcting the photometrical conditions on both surfaces of the film.

Abstract: An enlarger for use in photography capable of printing a color copy from a color original film includes a light source for generating a plurality of primary colors and a microcomputer for controlling the light source. The microcomputer has various functions which are: for providing a plurality of exposure data corresponding to a plurality of primary colors; for designating at least one of the primary colors; for altering the exposure data corresponding to the designated primary color; for displaying an information relating to the exposure data to be altered; for indicating the direction of change in tone of the color copy caused by altering the exposure data; for selecting the type of the original film; and for controlling the relation between the direction of change in tone of the color copy as indicated and the direction of change in the exposure data as displayed in response to the selected type of original film.

Abstract: A color enlarger for use in photography capable of printing a color copy from a color original film includes a plurality of source lights for separately generating lights corresponding to a plurality of primary colors; a monitor for separately picking-up the plurality of source lights to monitor the light generated from the light source, and light measuring circuit for separately measuring the plurality of source lights transmitted through the color original film. The color enlarger further includes a microcomputer which has various functions which are: for providing a color data representative of a color to be reproduced on the color copy; for separately calculating the whole light quantities for the plurality of source lights to be generated upon printing the color copy, in response to the monitor, the light measuring circuit, and the provided color data; and for controlling light sources upon printing the color copy in response to the calculating value.

Abstract: A color printer wherein densities of blue, green and red colors of an object copied print with respect to an original color picture for setting standard copying conditions by using the original color picture, a copied print is made by using the original color picture for setting standard copying conditions, densities of blue, green and red colors of the copied print are measured in an optical path of copying exposure, and the standard copying conditions are set on the basis of the functions of the measured densities of the object copied print and the copied print.

Abstract: A film has a series of exposed and developed negatives. Each negative is scanned at a multiplicity of regions, and the densities of each region in the three primary colors are measured. A blue/red density differential is derived for each region by subtracting the red density of a respective region from its blue density. The neutral density of each region is calculated, and every region is assigned a coordinate on a plot of blue/red density differential versus neutral density. According to one embodiment, the blue/red density differential for each region having a neutral density equal to or greater than a limiting value is then subtracted from the blue/red density differential given by a characteristic curve for the film. The differences obtained in this manner are analyzed, at least for selected negatives, and the minimum difference for each selected negative is determined. The region corresponding to the minimum difference is that region of a negative having the maximum blue density.