JP2000004361A - Image data correcting method and image processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire image data that accurately represents a subject image at the time of photographing from a read image data obtained by reading an image, which is exposed and recorded on photosensitive material and is visualized through development processing. SOLUTION: Characteristics data FilmDataj (d) which has conversion characteristics, that converts image data of a film image recorded on a photographic film into image data almost equal to image data of a virtual film image recorded on a virtual photographic film, having an exposure quantity-coloring density characteristics equal to characteristics obtd. by extending respectively linear parts of the exposure quantity-coloring density characteristics of the photographic film to an exposure quantity area where the characteristics become nonlinear is precalculated and nonlinear corrections that convert the image data by using the characteristics data are performed after performing the correction that corresponds to the bias of film base density to reference value. Furthermore, image data standardization, which corrects color balance of the image data in accordance with color balance of a gray candidate point in the image data, is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data correcting method and an image processing apparatus, and more particularly, to image data for correcting image data obtained by reading an image recorded on a photosensitive material by exposure and visualized by a developing process. The present invention relates to a correction method and an image processing apparatus to which the image data correction method can be applied.

[0002]

2. Description of the Related Art Conventionally, after performing various image processing on image data obtained by reading a film image recorded on a photographic film or image data input from a digital camera or the like, printing is performed. Image processing capable of outputting images in various output forms, such as recording images on recording materials such as paper, displaying images on display means such as displays, and storing image data on information recording media. Systems are known. According to this image processing system, the image quality of an output image can be freely controlled from the image processing system by performing image processing on image data, as compared with a conventional photographic processing system that records a film image on photographic paper by surface exposure. Higher output image quality can be realized.

[0003] A film image recorded on a photographic film has a large number of films recorded on a photographic film because the photographing conditions at the time of photographing are uncertain and the lighting conditions for a main subject such as a person are not constant. The images include film images whose image quality and the like are not appropriate due to the influence of shooting conditions, lighting conditions for the main subject, and the like. For example, a film image photographed by overexposure or underexposure has an overall high or low density and a compressed dynamic range. Assuming that image processing is performed on the image data of such a film image under the same processing conditions as a normal film image, the output image is a low-contrast image without sharpness. In addition, the film image of a backlight scene or a film image using a strobe at the time of shooting often has a large difference in density between a main part and a background part in the film image, and is similar to a normal film image. If image processing is performed under the processing conditions, the main image portion has an inappropriate density on the output image.

[0004] For this reason, the inventor of the present application has sought to obtain an output image of appropriate image quality even from the above-mentioned film image.
The state of the film image such as over / under, backlight, or flash photography is determined from the image information, and the intermediate density part of the image is not changed according to the image information and the determined image state, and the low density part and / or the image of the image is not changed. Japanese Patent Laid-Open No. 10-13 proposes a technique for independently setting processing conditions for nonlinearly compressing or decompressing high-density portions and performing image processing in accordance with the processing conditions to generate output image information.
No. 680).

[0005]

The decrease in the contrast of a film image photographed by overexposure or underexposure is caused by a change in the exposure amount-color density characteristic of a photographic film in an exposure region corresponding to overexposure or underexposure. Is generally smaller than the slope of change in the standard exposure amount range,
The exposure-color density characteristic of the photographic film changes non-linearly even within the exposure range corresponding to the over or under (the gradient (γ) of the color density change continuously changes with the exposure change). are doing). On the other hand, according to the technology described in the above-mentioned publication, processing conditions for uniformly compressing or expanding gradation in units of low-density portions or high-density portions of a film image according to an image state determined only from image information are set. Since the setting is set, in particular, image information of a film image photographed by overexposure or underexposure is often not accurately corrected in accordance with the exposure amount-coloring density characteristic of the photographic film.

In addition, the exposure-color density characteristics of a photographic film differ depending on the type of the photographic film, and strictly speaking, there are variations in photographic film lot units.
Further, the color density on a photographic film also changes depending on the developing conditions when the photographic film is subjected to a developing process.
On the other hand, the technique described in the above-mentioned publication determines the image state only from the image information and sets the processing condition,
The actual exposure-color density characteristics of the photographic film differ from each type of photographic film, vary from lot to lot, and vary depending on the development conditions. A corresponding accurate correction cannot be made. Therefore, it has been difficult to always obtain output image information that accurately represents a subject image at the time of shooting, even using the technique described in the above-mentioned publication.

The present invention has been made in view of the above-mentioned facts, and converts a subject image during exposure recording from read image data obtained by reading an image recorded on a photosensitive material by exposure and visualized by a development process. It is an object of the present invention to provide an image data correction method and an image processing device capable of acquiring image data that accurately represents an image.

[0008]

According to a first aspect of the present invention, there is provided an image data correcting method, comprising the steps of: storing characteristic data defined in accordance with an exposure amount-color density characteristic of a photosensitive material; Stored for each type, select characteristic data corresponding to the photosensitive material to be processed based on the type of the photosensitive material to be processed, and record the exposure data on the photosensitive material to be processed based on the selected characteristic data. The read image data obtained by reading the processing target image visualized by the developing process is used to calculate the exposure amount of the photosensitive material−
Exposure recording and development of the same subject as the image to be processed on a virtual photosensitive material having an exposure-color density characteristic equal to the linear portion of the color density characteristic extended to an exposure region where the characteristic becomes non-linear. The non-linearity correction is performed on the read image data so that the read image data becomes substantially equal to the virtual image data representing the virtual image obtained in step (1).

According to the first aspect of the present invention, characteristic data determined according to the exposure amount-coloring density characteristic of the photosensitive material is stored for each type of photosensitive material. The characteristic data may be data representing the exposure amount-coloring density characteristic itself of the photosensitive material, or the image density recorded on the photosensitive material, which is determined according to the exposure amount-coloring density characteristic of the photosensitive material. A virtual material recorded on a photosensitive material (a virtual photosensitive material having an exposure-color density characteristic equal to the linear portion of the exposure-color density characteristic of the photosensitive material extended to an exposure region where the characteristic becomes nonlinear). It may be data representing a conversion condition for converting to image density. When the photosensitive material is a color photosensitive material, the characteristic data is, for example, an exposure amount for each component color.
It may be determined for each component color according to the color density characteristic, or the characteristic data of the reference component color (for example, G) is determined according to the exposure-color density characteristic of the reference component color. The characteristic data of the component colors (for example, R and B) may be determined according to the difference between the exposure amount-coloring density characteristic of the reference component color and the exposure amount-coloring density characteristic of the other component colors.

According to a first aspect of the present invention, characteristic data corresponding to a photosensitive material to be processed is selected based on the type of the photosensitive material to be processed using the above-described characteristic data, and processing is performed based on the selected characteristic data. The read image data obtained by reading the processing target image that has been exposed and recorded on the target photosensitive material and visualized by the development process, the linear portion of the exposure-coloring density characteristic of the processing target photosensitive material has a non-linear characteristic. Virtual image data representing a virtual image obtained by exposing and recording the same subject as the image to be processed on a virtual photosensitive material having an exposure amount-coloring density characteristic equal to that extended to a certain exposure amount region and performing development processing. The non-linearity correction is performed on the read image data so as to be equal.

In the above-described nonlinearity correction, for example, when data representing a conversion condition for converting an image density into a virtual image density is used as the characteristic data as described above, the read image data is read in accordance with the conversion condition represented by the data. Can be performed by converting When data representing the exposure amount-coloring density characteristic of the photosensitive material itself is used as the characteristic data, for example, based on the exposure amount-coloring density characteristic represented by the characteristic data, the linear part of the characteristic is converted to a non-linear characteristic. Exposure amount-coloring density characteristic (exposure amount-virtual light-sensitive density characteristic of virtual photosensitive material) equal to the exposure amount range extended to
By associating the color density of the photosensitive material to be processed with the same exposure amount and the color density of the virtual photosensitive material over the entire exposure range based on both characteristics, the density of the image on the photosensitive material to be processed can be virtually determined. Non-linearity correction can be performed by determining a conversion condition for converting the density of the virtual image on the photosensitive material and converting the read image data in accordance with the conversion condition.

According to the first aspect of the present invention, characteristic data is stored for each type of photosensitive material, and characteristic data is selected based on the type of photosensitive material to be processed, and the nonlinear data described above is selected based on the selected characteristic data. Since the characteristic correction is performed, a change in density due to the non-linearity of the exposure-color density characteristic of the photosensitive material to be processed is corrected by the non-linear correction. Therefore, according to the first aspect of the present invention, from the read image data obtained by reading the image recorded on the photosensitive material by exposure and visualized by the developing process, the exposure amount of the photosensitive material-color developing density characteristic for each type of photosensitive material Regardless of the difference, image data that accurately represents the subject image at the time of exposure recording can be obtained.

The characteristic data may be data representing the exposure-color density characteristic itself of the photosensitive material as described above, but may be recorded on the photosensitive material as described in claim 2. It is preferable that the data is data representing a conversion condition for converting the density of the obtained image into the density of the virtual image recorded on the virtual photosensitive material. Accordingly, since the non-linearity can be corrected by converting the read image data according to the conversion condition represented by the characteristic data, the non-linearity can be corrected in a short time.

The exposure-coloring density characteristic of a photosensitive material such as a photographic film is generally nonlinear in an exposure region corresponding to underexposure or overexposure. The gradient of the change in the color density with respect to the change in the exposure amount is often smaller than γ in the exposure region where the linearity of the characteristic is maintained. Therefore, in the non-linearity correction, the image data in the density range where the exposure amount-coloring density characteristic is non-linear is corrected in a direction in which the gradation is hardened. It is also conceivable that the image represented has an undesired tone with excessively enhanced graininess of the film.

For this reason, the invention according to claim 3 is characterized in that the conversion condition according to claim 2 is determined such that the gradient of the conversion characteristic is equal to or less than a predetermined maximum value. As described above, by limiting the gradient of the conversion characteristic, it is possible to prevent the image data from being converted so that the image represented by the image data has an undesired image in which the graininess of the film is excessively emphasized. .

According to a fourth aspect of the present invention, in the first aspect of the invention, the photosensitive material is a photographic film, and the density of the film base of the photographic film to be processed is detected and detected prior to execution of the nonlinearity correction. It is characterized in that the read image data or the characteristic data of the photographic film is corrected in advance so that the density of the film base substantially matches the density of the film base defined by the characteristic data of the photographic film.

The density of the film base of the photographic film varies depending on the developing conditions when the photographic film is subjected to the development processing, and the variation in the density of the film base is added to the read image data as an offset. On the other hand, in the invention of claim 4, prior to execution of the non-linearity correction, the density of the film base of the photographic film to be processed is detected, and the film density defined by the detected density of the film base and the characteristic data of the photographic film. Since the read image data or the characteristic data of the photographic film is corrected in advance according to the difference from the density of the base, the developing conditions when the developing process is performed on the photographic film to be processed are different from the standard developing conditions. Even if it is, the density fluctuation of the film base due to the difference of the developing condition is corrected. Therefore, according to the fourth aspect of the present invention, it is possible to eliminate the influence of the fluctuation of the film base density of the photographic film caused by the fluctuation of the developing condition from the image data representing the subject image at the time of the exposure recording.

The image recorded on the photographic film is read optically (for example, light emitted from a light source is applied to a portion of the photographic film where the image is recorded, and transmitted through the photographic film (or In many cases, the amount of reflected light is detected by a sensor). Even when the amount of light emitted from the light source when reading the image to be processed is different from the predetermined amount, this difference in the amount of light is It is added to the read image data as an offset. Therefore, in the invention according to claim 4, the density of the film base is measured using the light source and the sensor used for reading the image to be processed, or the read image data includes data representing the density of the film base. In this case, if the data representing the film base density is extracted from the read image data instead of the measurement of the film base density, the light source used for reading the image to be processed by the correction according to claim 4 The offset of the read image data due to the change in the amount of light emitted from the camera can also be corrected.

Incidentally, the exposure amount-coloring density characteristic of a color photosensitive material is originally different for each component color (even when developed under standard developing conditions), and the light- When the developing conditions at the time of processing are changed, the actual exposure amount-coloring density characteristic of the color photosensitive material further varies separately for each component color. The color balance of the image recorded on the photosensitive material deviates from the color balance of the subject image at the time of exposure recording due to the difference between the exposure amount and the color density characteristic of each component color. Therefore, in the invention according to claim 5, in the invention according to claim 1, normalization of the image data for correcting the density balance of each component color of the image data based on at least the read image data and non-linearity correction are performed. It is characterized in that it is performed on the previously read image data or image data obtained by performing the non-linearity correction.

The color balance of the image to be processed represented by the read image data reflects the actual exposure amount-color density characteristic of the photosensitive material which changes under the influence of the development condition fluctuation. The color balance of the pixels on the processing target image corresponding to the achromatic portion on the subject image indicates the difference between the actual exposure amount and the color density characteristic of the photosensitive material for each component color. Therefore, by standardizing image data for correcting the density balance of each component color of the image data based on at least the read image data, the original exposure amount-coloring density characteristic of the photosensitive material for each component color can be obtained. It is possible to correct the deviation of the density balance of each component color of the processing target image caused by the difference and the difference of the exposure amount-coloring density characteristic of each component color due to the fluctuation of the development condition.

As described above, according to the fifth aspect of the present invention, the density balance of each component color of the image data representing the subject image at the time of exposure recording can be made appropriate. The standardization of image data for correcting the density balance of each component color of the image data based on at least the read image data is performed, for example, on the basis of pixel data whose hue on the subject image is estimated to be achromatic from the read image data. Is extracted, a correction amount of the density balance for the image data is determined based on the density balance of each component color of the pixel, and the image data is corrected based on the determined correction amount.

Further, since the image content of the processing target image (the subject image exposed and recorded on the photosensitive material) is undefined, if the density balance of each component color is corrected based only on the read image data, the processing target image Depending on the image content, the correction accuracy may be significantly reduced. For this reason, the invention according to claim 6 stores characteristic data determined according to the exposure amount-coloring density characteristic of the photosensitive material for each type of photosensitive material,
Analyzing the processing target image using the read image data obtained by reading the processing target image visualized by exposure processing is recorded on the photosensitive material of the processing target, and developed,
Based on the result of the analysis, a weight for each of the normalization based on the read image data and the standardization based on the characteristic data is determined, and the normalization based on the read image data and the normalization based on the characteristic data are determined according to the determined weight. The image data for correcting the density balance of each component color of the image data by performing weighting of the image data is normalized.

Since the characteristic data is data determined according to the exposure-color density characteristic of the photosensitive material, the image data for correcting the density balance of each component color of the image data is standardized based on the characteristic data. In this case, it is possible to correct at least the deviation of the density balance of each component color caused by the difference of the original exposure amount-coloring density characteristic of the photosensitive material for each component color. In the invention according to claim 6, weights for normalization based on read image data and normalization based on characteristic data are respectively determined based on a result of analyzing a processing target image, and weights for both normalizations are determined according to the determined weights. Since the image data is normalized by performing the correction, when the image to be processed has an image content in which the correction accuracy is significantly reduced when the density balance of each component color is corrected based only on the read image data, etc. In addition, it is possible to prevent the accuracy of correcting the density balance of each component color from being significantly reduced. Therefore, according to the sixth aspect of the present invention, it is possible to acquire image data that accurately represents a subject image at the time of exposure recording from read image data.

To normalize image data by weighting the normalization based on the read image data and the normalization based on the characteristic data, specifically, for example, a normalization condition is obtained based on the read image data. In addition, a normalization condition is obtained based on the characteristic data, a weighted average of the two normalization conditions is calculated according to the determined weight, and the density balance of each component color of the image data is corrected according to the normalization condition obtained by the calculation. That can be done.

According to the fifth aspect of the present invention, as described above, the standardization based on the read image data and the standardization based on the characteristic data are performed based on the result of analyzing the processing target image using the read image data. Needless to say, the weights may be determined, and the normalization based on the read image data and the normalization based on the characteristic data may be weighted in accordance with the determined weights to normalize the image data.

By the way, the correction accuracy based on the standardization condition obtained based on the read image data can be estimated from various parameters that define the image content of the image to be processed. In the case where the data of the pixel whose hue is estimated to be an achromatic color is extracted and the normalization condition for the image data is determined based on the density balance of each component color of the pixel, the normalization based on the read image data is performed. As described in claim 7, the weight for the normalization condition based on the condition and the characteristic data is, as analysis of the processing target image, the data of the pixel whose hue on the subject image is estimated to be an achromatic color from the read image data. It is preferable to perform extraction and determine based on the number of extracted pixels.

Various methods have been conventionally proposed for extracting data of pixels whose hue on the subject image is estimated to be achromatic. There is a possibility that pixels having a non-achromatic color on the subject image are mixed. Therefore, it is desirable to extract a large number of data of pixels whose hue on the subject image is estimated to be achromatic, and obtain the standardization condition based on an average density balance represented by the data of the extracted many pixels. However, if the number of pixels extracted as pixels whose hue on the subject image is estimated to be achromatic is small, the correction accuracy based on the standardization condition obtained based on the read image data may be reduced. high.

On the other hand, as an analysis of the image to be processed,
Based on the read image data, the data of the pixel whose hue on the subject image is estimated to be achromatic is extracted, and the normalization condition based on the read image data and the normalization condition based on the characteristic data are determined based on the number of extracted pixels. If the weight is determined (more specifically, the weight of the normalization condition based on the read image data is reduced as the number of extracted pixels is reduced), it is always possible to obtain a high correction accuracy for each component color of the image data. The density balance can be corrected.

According to an eighth aspect of the present invention, there is provided an image processing apparatus, comprising: storage means for storing, for each type of photosensitive material, characteristic data determined in accordance with the exposure-color density characteristic of the photosensitive material; Selecting means for selecting characteristic data corresponding to the photosensitive material to be processed among the characteristic data stored in the storage means, based on the type of the photosensitive material, and exposing and recording the photosensitive material to be processed and visualized by development processing. Reading means for reading the image to be processed, and, based on the selected characteristic data, read image data obtained by reading the image to be processed by the reading means, the linearity of the exposure-color density characteristic of the photosensitive material. Exposure recording of the same subject as the image to be processed on a virtual photosensitive material having an exposure-color density characteristic equal to that obtained by extending the portion to an exposure area where the characteristic becomes nonlinear. To be substantially equal to the virtual image data representing a virtual image obtained by performing a development process, it is configured to include a correction means for performing nonlinear correction on the read image data.

According to the present invention, the characteristic data determined in accordance with the exposure amount-color density characteristic of the photosensitive material is stored in the storage means for each type of the photosensitive material, and the processing object selected by the selection means is selected. The read image data obtained by reading the image to be processed by the reading unit based on the characteristic data corresponding to
By exposing and recording the same subject as the image to be processed on a virtual photosensitive material having the same exposure-color density characteristics as the linear portion of the color density characteristics extended to the exposure region where the characteristics become non-linear, and performing development processing. 2. A non-linearity correction is performed on read image data by a correction unit so as to be substantially equal to virtual image data representing an obtained virtual image.
Similarly to the invention, image data accurately representing a subject image at the time of exposure recording can be acquired from read image data obtained by reading an image exposed and recorded on a photosensitive material and visualized by a development process.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] First, a digital lab system according to a first embodiment including an image processing apparatus according to the present invention will be described.

(Schematic Configuration of Entire System) FIG. 1 shows a schematic configuration of a digital laboratory system 10 according to the present embodiment, and FIG. 2 shows an appearance of the digital laboratory system 10. As shown in FIG. 1, the lab system 10 includes a line CCD scanner 14, an image processing unit 1
6, a laser printer section 18 and a processor section 20. The line CCD scanner 14 and the image processing section 16 are integrated as an input section 26 shown in FIG. Part 20
Are integrated as an output unit 28 shown in FIG.

The line CCD scanner 14 scans a film image (photographing an object, developing processing, For example, a 135-size photographic film, a 110-size photographic film, and a photographic film on which a transparent magnetic layer is formed (a 240-size photograph) Film: so-called APS film), 120 size and 22
A film image of a photographic film of size 0 (Brownie size) can be read. The line CCD scanner 14 reads the film image to be read by a three-line color CCD, and outputs R, G, and B image data.

As shown in FIG. 2, the line CCD scanner 14 is mounted on a work table 30. The image processing section 16 is stored in a storage section 32 formed below the work table 30, and an opening / closing door 34 is attached to an opening of the storage section 32. Normally, the inside of the storage unit 32 is concealed by the open / close door 34, and when the open / close door 34 is rotated, the inside is exposed, and the image processing unit 16 can be taken out.

The work table 30 has a display 164 on the back side and two types of keyboards 166A and 166B. One keyboard 166 </ b> A is embedded in the work table 30. The other keyboard 166B is housed in the drawer 36 of the work table 30 when not in use, and is taken out of the drawer 36 when used and is arranged on the keyboard 166A. When the keyboard 166B is used, a connector (not shown) attached to the tip of a cord (signal line) extending from the keyboard 166B,
The keyboard 166 </ b> B is electrically connected to the image processing unit 16 via the jack 37 by being connected to the jack 37 provided on the work table 30.

A mouse 40 is arranged on the work surface 30U of the work table 30. The mouse 40 has a code (signal line) extending through the hole 42 provided in the work table 30 into the storage unit 32.
Is connected to The mouse 40 is stored in the mouse holder 40A when not in use, and is taken out of the mouse holder 40A when in use and placed on the work surface 30U.

The image processing unit 16 receives image data (scan data) output from the line CCD scanner 14 and obtains image data obtained by photographing with a digital camera and a document other than a film image (for example, a reflection document). ) Is input from outside (for example, via a storage medium such as a memory card). Or input from another information processing device via a communication line, etc.).

The image processing section 16 performs image processing such as various corrections on the input image data and outputs the image data to the laser printer section 18 as recording image data. Also,
The image processing unit 16 outputs image data on which image processing has been performed to an external device as an image file (for example, outputs the image data to a storage medium such as a memory card, or transmits the image data to another information processing device via a communication line). It is also possible.

The laser printer section 18 is provided with R, G, and B laser light sources, and irradiates a photographic paper with laser light modulated in accordance with recording image data input from the image processing section 16 to perform scanning exposure. To record an image on photographic paper. Further, the processor unit 20 performs each process of color development, bleach-fix, washing, and drying on the photographic paper on which the image is recorded by the scanning exposure by the laser printer unit 18. Thus, an image is formed on the printing paper.

(Configuration of Image Processing Unit) Next, the image processing unit 16
Will be described with reference to FIG. Image processing unit 1
6 is R input from the line CCD scanner 14,
The line scanner correction unit 122 corresponding to the G and B data
R, 122G, and 122B are provided. The line scanner correction units 122R, 122G, and 122B have the same configuration, and are hereinafter generically referred to as “line scanner correction unit 122” without distinction.

The line scanner correction unit 122 outputs the line C
Line CC by CD reading photographic film
When scan data is input from the D-scanner 14, dark correction for reducing the dark output level of a cell corresponding to each pixel from the input scan data, and data obtained by performing the dark correction are logarithmically converted to data representing the density of a photographic film. Density conversion for conversion, shading correction for correcting the data subjected to the density conversion in pixel units according to the unevenness in the amount of light illuminating the photographic film, and accurately corresponds to the amount of incident light in the data subjected to the shading correction The processing of the defective pixel correction which is newly generated by interpolating the data of the cell (so-called defective pixel) to which the output signal is not output from the data of the surrounding pixels is sequentially performed.

The output terminal of the line scanner correction unit 122 is connected to the input terminal of the selector 132, and the data subjected to each of the above-described processes in the line scanner correction unit 122 is input to the selector 132 as scan data. Also,
The input end of the selector 132 is also connected to the data output end of the input / output controller 134, from which file image data input from the outside is input to the selector 132. The output terminal of the selector 132 is connected to the input / output controller 134 and the data input terminals of the image processors 136A and 136B. The selector 132 converts the input image data into an input / output controller 134 and an image processor 136.
A and 136B can be selectively output.

The image processor section 136A includes a memory controller 138, an image processor 140, and three frame memories 142A, 142B, 142C. Frame memories 142A, 142B, 142C
Have a capacity capable of storing image data of one or more frames of film images, and the image data input from the selector 132 is stored in one of the three frame memories 142 by the memory controller 138. You.

As shown in FIG. 4, the image processor 140 according to the first embodiment has a first image processing unit 140.
A, offset correction unit 140B, nonlinearity correction unit 140
C, an image data normalizing unit 140D, and a second image data processing unit 140E are connected in this order, and a frame memory 142 (the fine scan memory 14 in FIG.
2), and performs various image processing according to processing conditions determined for each image by an auto setup engine 144 (described later). Note that the offset correction unit 1
40B performs an offset correction process, and performs a non-linearity correction unit 1
40C performs a non-linearity correction process, and the image data normalization unit 140D performs an image data normalization process. These processes will be described later.

Further, the first image processing unit 140A and the second
The image processing executed by any of the image processing units 140E includes, for example, image enlargement / reduction, gradation conversion, color conversion, hypertone processing for compressing the gradation of an ultra-low frequency luminance component of the image, and suppression of graininess. Image processing (standard image processing) for improving the image quality of an output image, such as hyper-sharpness processing that emphasizes sharpness while performing the image processing. In addition, image processing for improving the image quality of an output image when an image photographed and recorded by a film with a lens or the like is used as an original image (for example, distortion of the original image due to lens distortion or magnification of the original image due to chromatic aberration of magnification of the lens). Image processing for correcting color blur, image processing for intentionally changing the image tone (for example, image processing for finishing the output image in monotone, image processing for finishing the output image in portrait tone, and image for finishing the output image in sepia tone) Processing, etc.) and image processing (for example, image processing for finishing a person present in the original image into a slender body on the main image), etc. A first image processing unit 140A and a second image processing unit that can also execute non-standard image processing to be selectively executed in units of a plurality of images such as a group of recorded images. It may form at least one of 40E.

The image processor 140 is connected to the input / output controller 134. The image data subjected to the image processing is temporarily stored in the frame memory 142 and then output to the input / output controller 134 at a predetermined timing. Note that the image processor unit 136B has the same configuration as the above-described image processor unit 136A, and a description thereof will be omitted.

In the present embodiment, each line image is read twice by the line CCD scanner 14 at different resolutions. In the first reading at a relatively low resolution (hereinafter, referred to as pre-scan), even when the density of the film image is extremely low (for example, a negative image of an underexposure in a negative film), a line CCD is used.
The reading of the entire surface of the photographic film is performed under the reading conditions determined so that the accumulated charge does not saturate (the amount of light irradiating the photographic film in each of the R, G, and B wavelength ranges, and the charge storage time of the line CCD). Done. Data (pre-scan data) obtained by this pre-scan is output from the selector 132 to the input / output controller 134.

An automatic setup engine 144 is connected to the input / output controller 134. The auto setup engine 144 includes a CPU 146, a RAM 14
8 (for example, a DRAM), a ROM 150 (for example, a ROM whose storage content can be rewritten), and an input / output port 152.
These components are connected to each other via a bus 154. The pre-scan data output from the input / output controller 134 is stored in the pre-scan memory 13 shown in FIG.
After the data is temporarily stored in the storage unit 5, it is subjected to a setup calculation process in an auto setup engine 144 and a simulation image display process in a personal computer 158 (described later). Note that the prescan memory 135 is actually the RAM 148 of the auto setup engine 144 or the personal computer 1.
58 (described later) is used.

FIG. 4 shows the auto setup engine 14.
4 among various functions realized by the CPU 146.
The function of performing the setup calculation processing is shown as a setup calculation unit 144A. This setup operation unit 1
The 44A performs the setup calculation processing as follows. That is, the setup calculation unit 144A determines the frame position of the film image based on the pre-scan data input from the input / output controller 134, and converts data (pre-scan image data) corresponding to the film image recording area on the photographic film. Extract. Further, based on the pre-scanned image data, the size of the film image is determined, and image features such as density are calculated.
Determines the reading conditions when re-reading at a relatively high resolution (hereinafter, referred to as fine scan). Then, the frame position and the reading conditions are output to the line CCD scanner 14.

The setup calculation unit 144A performs image processing on image data (fine scan image data) obtained by performing fine scan by the line CCD scanner 14 based on prescan image data of film images for a plurality of frames. Are automatically determined by calculation, and the determined processing conditions are output to the image processor 140 of the image processor unit 136. The determination of the processing conditions of this image processing is performed by determining whether there are a plurality of film images capturing similar scenes based on the exposure amount at the time of capturing, the type of capturing light source, and other feature amounts, and determining a plurality of film images capturing similar scenes. Are determined, the processing conditions for image processing for these film images are the same or similar.

The optimum processing conditions for the image processing are as follows: whether the image data after the image processing is used for recording an image on photographic paper in the laser printer unit 18 or for displaying on a display means such as a display. It also changes depending on whether it is stored in the information recording medium or the like. Since the image processing unit 16 is provided with two image processor units 136A and 136B, for example, in a case where image data is used for recording an image on photographic paper and output to the outside, the setup calculation unit 144A Performs a set-up operation for each application, determines optimum processing conditions for each application, and outputs it to the image processor units 136A and 136B. Thus, the image processors 136A and 136B perform image processing on the same fine scan image data under different processing conditions.

Further, the setup calculation section 144A defines the gray balance and the like when the laser printer section 18 records an image on photographic paper based on the prescanned image data of the film image input from the input / output controller 134. The image recording parameters are calculated and output at the same time as the recording image data (described later) is output to the laser printer unit 18. Also, the auto setup engine 14
Reference numeral 4 also determines the image processing conditions for the file image data input from the outside by calculation in the same manner as described above.

The auto setup engine 144
ROM150 stores characteristic data FilmData _j (d) determined in accordance with the exposure-color density characteristics of the photographic film (where d represents the density, and j is any of R, G, and B). Represents). The characteristic data FilmData _j (d) is the density value represented by the image data of the film image recorded on the photographic film,
(LogH) -R, G, B equal to the linear part of the color density (d) characteristic extended to the exposure region where the characteristic becomes non-linear.
The same exposure value as the density value represented by virtual image data representing a virtual film image obtained by exposing and recording the same subject as the film image on a virtual photographic film having a color density characteristic and developing the same. FIG. 5A shows conversion conditions for converting the image data of the film image (non-linear positive correction according to the present invention).
As shown in FIG.

The characteristic data FilmData _j (d) can be determined, for example, as follows. That is, as shown in FIG. 6A, for example, the exposure-color density characteristic of a negative film, which is a kind of photographic film, shows a change in the exposure in a standard exposure range corresponding to normal exposure. Although the color density varies linearly (in direct proportion), in an exposure area corresponding to underexposure and an exposure area corresponding to overexposure, γ increases as the distance from the standard exposure area increases.
(Slope of change in color density with change in exposure amount) gradually decreases, and color density changes non-linearly with change in exposure amount. Therefore, as shown by the bold line in FIG. 6B, the linear portion of the characteristic is extended to the exposure region where the characteristic becomes nonlinear with respect to the exposure-color density characteristic of the photographic film to be processed. A proper exposure-color density characteristic is set. This corresponds to the exposure-color density characteristics of the virtual photographic film described above.

Next, the exposure amount of the photographic film to be processed is
In the color density characteristics and the exposure-color density characteristics of the virtual photographic film, the color density for the same exposure is associated over the entire exposure range. For example, as shown in FIG. 6, the color density d ₁ of the photographic film to be processed with respect to the exposure amount H ₁ associates the color density d ₁ 'of the virtual photographic film, color development of photographic film to be processed with respect to the exposure amount H ₂ Density d ₂ and color density d ₂ ′ of virtual photographic film
Associating the door, associated with a color density d ₃ of the photographic film to be processed with respect to the exposure amount H ₃ and color density d ₃ 'of the virtual photographic film.

Then, among the associated color densities, the color density of the photographic film to be processed is defined as the input density, and the color density of the virtual photographic film is defined as the output density. Is set to convert the density into a density value of a virtual image recorded on the virtual photographic film. By performing the above processing for each of the R, G, and B component colors, characteristic data FilmData _j (d) representing the conversion condition of the conversion characteristic as shown in FIG. 5A is obtained.

Since the exposure-color density characteristics of the photographic film are different for each film type of the photographic film, in the present embodiment, the above characteristic data FilmData _j (d) is set for each film type. I have. The ROM 150 stores characteristic data FilmData _j (d) of each film type in association with information for identifying the film type. Therefore, the ROM 150 stores the characteristic data storage unit 14 shown in FIG.
It has a function as 4B and corresponds to the storage means according to claim 8. Also, the characteristic data storage unit 144B
The characteristic data FilmData _j (d) stored in the above corresponds to the characteristic data described in claim 2 in more detail.

When the image data is converted in accordance with the above-mentioned characteristic data FilmData _j (d), the gradation is hardened for the image portion of the density region corresponding to underexposure and the density region corresponding to overexposure. In other words, if the contrast is excessively high, the image tone of the image portion may be an undesired image tone in which the graininess of the film is excessively emphasized. Therefore, when setting the characteristic data FilmData _j (d),
The gradient of the conversion characteristic (θ shown in FIG. 5A) is set to be equal to or less than a predetermined maximum value. As a result, it is possible to prevent the image represented by the image data converted by the characteristic data FilmData _j (d) from having an undesired tone in which the graininess of the film is excessively emphasized. Setting the characteristic data FilmData _j (d) as described above
This corresponds to the invention of claim 3.

The input / output controller 134 is an I / F circuit 1
It is connected to the laser printer section 18 via 56.
When the image data after image processing is used for recording an image on photographic paper, the image data processed by the image processor 136 is transferred from the input / output controller 134 via the I / F circuit 156 to the recording image. The data is output to the laser printer unit 18 as data. The auto setup engine 144 is connected to a personal computer 158. When the image data after the image processing is output to the outside as an image file, the image data processed by the image processor unit 136 is sent from the input / output controller 134 to the auto setup engine 144.
Is output to the personal computer 158 via the.

The personal computer 158 has a CPU
160, a memory 162, a display 164, a keyboard 166, a hard disk 168, a CD-ROM driver 170, a transport control unit 172, an expansion slot 174, and an image compression / decompression unit 176.
8 are connected to each other.

FIG. 4 shows, among the various functions realized by the CPU 160 of the personal computer 158, a function relating to the simulation image display processing by a plurality of blocks (that is, a prescan image data processing section 158A, an image display section 158B) for each function. And key correction input unit 1
58C). The pre-scan image data processing unit 158A takes in the pre-scan image data extracted from the pre-scan data by the setup operation unit 144A and re-stored in the pre-scan memory 135 from the pre-scan memory 135, and is determined by the setup operation unit 144A. Based on the acquired processing conditions, image processing equivalent to the image processing performed by the image processor 140 on the fine-scan image data is performed on the pre-scan image data based on the captured processing conditions, thereby obtaining simulation image data. Generate.

The image display section 158B is connected to the display 164.
The simulation image data generated by the pre-scan image data processing unit 158A is converted into a signal for displaying an image on the display 164, and the simulation image is displayed on the display 164 based on the signal. I do. The key correction input section 158C includes a keyboard 166,
The operator performs verification of image quality or the like on the simulation image displayed on the display 164, and when information for instructing correction of processing conditions is input via the keyboard 166 as a verification result, the information is transmitted to the auto setup engine 144 ( Setup operation section 144A)
Output to Thereby, the setup operation unit 144A
In, processing such as recalculation of processing conditions of image processing is performed.

On the other hand, the transport control section 172 has a line CCD
It is connected to a film carrier 38 set on the scanner 14 and controls the transport of the photographic film by the film carrier 38. Also, the film carrier 38 has A
When the PS film is set, information (for example, print size) read by the film carrier 38 from the magnetic layer of the APS film is input.

A driver (not shown) for reading / writing data from / to an information storage medium such as a memory card and a communication control device for communicating with other information processing devices are provided via the expansion slot 174. Connected to the personal computer 158. I / O controller 134
When image data for output to the outside is input from an external device (such as the driver or the communication control device) as an image file via the expansion slot 174,
Is output to When file image data is input from outside via the expansion slot 174, the input file image data is output to the input / output controller 134 via the auto setup engine 144. In this case, the input / output controller 134 outputs the input file image data to the selector 132.

(Operation) Next, as an operation of the present embodiment, a film image recorded on a photographic film is
A case will be described in which the image data is read by the D scanner 14 and various image processes are performed on the image data obtained by the reading and output.

As described above, the line CCD scanner 14 reads the film image recorded on the photographic film twice (pre-scan and fine scan). The prescan is performed by the line CCD scanner 14 over the entire surface of the photographic film to be processed (read), and when the prescan data is input from the line CCD scanner 14 to the image processing unit 16, the input prescan data For the line scanner correction unit 1
22, dark correction, density conversion, shading correction,
Each process of defective pixel correction is performed.

The pre-scan data output from the line scanner correction unit 122 is temporarily stored in the pre-scan memory 135 via the selector 132 and then taken into the auto-setup engine 144, and the (setup-operation unit 144A of the auto-setup engine 144) )
Executes the setup calculation process. Hereinafter, the setup calculation process will be described with reference to the flowchart of FIG.

In step 300, data of an area where a bar code (DX code) is recorded on the photographic film to be processed is extracted from the pre-scan data fetched from the pre-scan memory 135, and the next step 302
Then, the contents of the DX code recorded on the photographic film to be processed are determined from the data extracted in step 300,
The type of the photographic film to be processed is determined based on the determined content. In step 304, the ROM 150
(I.e. the characteristic data storage unit 144B) from the characteristic data FilmData _j for each film type stored (d), the capture film type to the corresponding characteristic data FilmData _j of processed photographic film (d). Then, in the next step 306, the acquired characteristic data FilmData _j (d) is set as a conversion condition for nonlinearity correction. This step 304 corresponds to the selecting means described in claim 8.

In step 308, data of an unexposed area (absent area) on the photographic film to be processed is extracted from the prescan data fetched from the prescan memory 135, and R, G, B represented by the extracted data. The density value of the film base density of the photographic film to be processed.
Set as eDns _j . This step 308 corresponds to the detection of the density of the film base according to the fourth aspect. In the next step 310, the minimum densities of R, G, and B defined by the characteristic data FilmData _j (d) fetched in the previous step 304 are respectively set as reference values BaseData _j of the film base densities. And step 3
In 12, the reference value BaseData _j of the film base density BaseDns _j and film base density, is stored as the offset correction value for the photographic film to be processed.

In the following steps 314 to 320, processing is performed for each film image. That is, in step 314, the recording position (frame position) of one frame of the film image on the photographic film is determined based on the prescan data fetched from the prescan memory 135, and the prescan data is determined based on the determined frame position. , The film image data IMAGE _j (x) corresponding to the film image recording position is cut out (where x represents an ID for identifying each pixel). This film image data I
MAGE _j (x) (that is, pre-scan image data) corresponds to the read image data according to the present invention.

In step 316, the disconnection is made in step 314.
Film image data IMAGE _j(x)
Using the offset correction value stored in step 312,
According to the equation (1), each pixel data is used as a unit.
Perform the offset correction processing.

IMAGE2 _j (x) = IMAGE _j (x) −BaseDns _j + BaseData _j (1) The density of the film base of the photographic film fluctuates depending on the development conditions when the photographic film is subjected to the development processing.
This film-based density variation is based on the film image data.
Add to IMAGE _j (x) as an offset. Also, when the photographic film is read by the line CCD, if the amount of light emitted from the light source used for reading is different from the expected amount of light, this difference in the amount of light will be reflected in the film image data IMAGE.
_Add as an offset to _j (x). In contrast, in the above offset correction processing, the film base density BaseDns
_Since the film image data IMAGE _j (x) is corrected in accordance with the difference between _j and the film base density reference value BaseData _j , fluctuations in the development conditions of the development processing for the photographic film to be processed, It is possible to correct the offset of the film image data IMAGE _j (x) due to the fluctuation of the light amount of the light source.

In the next step 318, offset correction is performed.
Film image data IMAGE2 after processing _j(x)
Characteristics data FilmData captured in step 304_j(d)
And the data of each pixel is simply calculated according to the following equation (2).
Non-linearity correction processing is performed for each of R, G, and B as positions.

IMAGE3 _j (x) = FilmData _j (IMAGE2 _j (x)) (2) By the above-described non-linearity correction processing, the influence of the non-linearity of the exposure-color density characteristic of the photographic film to be processed is removed. , Film image data IMAG after offset correction processing
E2 _j (x) is an exposure-color density characteristic (FIG. 6) in which the color density changes linearly with the change in the exposure over the entire density range.
This is converted into image data (film image data IMAGE3 _j (x)) substantially equal to the image data of the virtual film image recorded on the virtual photographic film having (B) the thick photographic film. Step 318 corresponds to the nonlinearity correction described in claim 1 (correction means described in claim 8).

In the next step 320, it is determined whether or not the above-described steps 314 to 318 have been performed on all the film images recorded on the photographic film to be processed. If the determination is negative, step 314 is reached.
Returning to step 320, steps 314 to 320 are repeated until the determination in step 320 is affirmed. Thus, the film image data IMAGE3 _j (x) after the non-linearity correction processing is obtained for all the film images.

Incidentally, the exposure-color density characteristics of a photographic film differ for each of R, G, and B even when developed under standard development conditions. Deviates from the standard development conditions, the actual exposure-color density characteristics of the photographic film further vary separately for each of R, G, and B. Therefore, the color balance of the image represented by the film image data IMAGE3 _j (x) after the non-linearity correction processing is determined by the difference between the R, G, and B of the actual exposure amount-color density characteristics of the photographic film. At the time of exposure (at the time of exposure recording of the subject image on the photographic film) (the gray balance is lost). For this reason, in the next step 322 and subsequent steps, the image data is normalized so that the color balance of the image represented by the image data substantially matches the color balance of the subject image.

[0078] At step 322, analyzes the respective film image based on the nonlinearity correction process after the film image data image3 _j for each film image (x), from the film image data image3 _j for each film image (x), Pixels (gray candidate points) corresponding to portions where the hue is estimated to be achromatic (eg, gray) on the subject image captured and recorded on the photographic film to be processed as the processing target film image are extracted. The extraction of the gray candidate points can be performed, for example, as follows.

That is, based on the film image data IMAGE3 _j (x) of each film image, for each film image, the high density side R, which represents the condition of achromatic color on the high density side,
The low-density R, G, and B reference densities representing the achromatic color conditions on the G and B reference densities and the low-density side are set, respectively. As the R, G, and B reference densities on the high density side and the low density side, for example, the color of a pixel having the maximum three-color average density in the film image and the color of the pixel having the minimum three-color average density (the pixel Hue of the corresponding part corresponding to, the same applies hereinafter) is regarded as achromatic,
The R, G, B density values of the pixel can be used as the R, G, B reference densities on the high density side and the low density side. Further, in the density histogram of the three-color average density, the tint of a pixel whose cumulative frequency from the maximum value and the minimum value of the three-color average density is a predetermined value is regarded as an achromatic color, and the R, G, and B density values of the pixel are set to high. The R, G, and B reference densities on the density side and the low density side may be used, or the average density for each of R, G, and B of a plurality of pixels whose cumulative frequency from the maximum value of the three-color average density is within a predetermined range may be high. On the density R, G, and B reference densities, the average density for each of R, G, and B of a plurality of pixels whose cumulative frequency from the minimum value of the three-color average density is within a predetermined range is the low density R, G, and B reference. The concentration may be used.

Next, in order to improve the accuracy of the R, G, and B reference densities, the average of the R, G, and B reference densities for the R, G, and B reference densities respectively set for each film image is set. Values (average R, G, B reference densities on the high density side), low density R,
The average value of the G and B reference densities for each of R, G, and B (low-density average R, G, and B reference densities) is calculated.

Subsequently, based on the high-density-side average R, G, and B reference densities and the low-density-side average R, G, and B reference densities, the three-color average density of each pixel of the film image and the tint of each pixel are determined. The achromatic condition representing the relationship between R, G, and B densities when is achromatic is determined. For example, as shown in FIG. 8, the high-density-side average is displayed on the color coordinate (in FIG. 8, the color coordinate with the R density-G density on the horizontal axis and the G density-B density on the vertical axis is shown as an example). The R, G, B reference densities and the low-density average R, G, B reference densities are plotted, for example, they are connected by a straight line (referred to as an achromatic line), and the film image data IMAGE3 _j (x ), A large number of pixel data in which the R, G, and B densities fall within a certain range around the achromatic line (for example, a range surrounded by a broken line in FIG. 8) are extracted. From the data, an achromatic condition representing the relationship between the average density of three colors and the R, G, and B densities of each pixel can be determined by the least square method, regression analysis, or the like.

The achromatic condition is defined as achromatic pixels in the film image (pixels corresponding to gray portions in the subject image).
Represents the density balance of R, G, and B (color balance in each density range), and extracts a pixel matching the achromatic color condition as a gray candidate point. The method for extracting gray candidate points is not limited to the above, and various known extraction methods can be applied. In step 322, from among the gray candidate points extracted as described above,
A pixel in a density range corresponding to a linear portion in the exposure-color density characteristic of the photographic film to be processed is extracted as a final gray candidate point.

In the next step 324, film image data IMAGE3 _j (x) used in the normalization processing of the image data
The weighting factor α ₁ for the normalization condition obtained from, and the weighting factor α ₂ for the normalization condition obtained from the characteristic data FilmData _j (d) are determined. The weighting coefficients α ₁ and α ₂ are calculated from the film image data IMAGE3 _j (x) based on the number of gray candidate points finally extracted from each film image and as the number of extracted gray candidate points increases. can be determined so that the value of the weighting factor alpha ₁ for the obtained normalized condition increases. Note that the above steps 322, 324
Corresponds to the invention of claim 6 (more specifically, the invention of claim 7).

By the way, matching the color balance of the image represented by the image data with the color balance of the subject image depends on the relationship between the exposure amount of R at the time of photographing and the density of R on the image represented by the image data, The relationship between the exposure amount of G and the density of G on the image represented by the image data and the relationship between the exposure amount of B at the time of shooting and the density of B on the image represented by the image data match (overlap). As described above, it can be realized by converting the image data using the data of each pixel as a unit.

In the first embodiment, since the normalization processing is performed on the film image data IMAGE3 _j (x) after the execution of the non-linearity correction, the above relations for each of the R, G, and B colors are linear. . Therefore, the normalization processing (processing for making the relationship between the exposure amount at the time of shooting for each of R, G, and B colors and the density on the image represented by the image data substantially match) according to the first embodiment is performed by using film image data. For IMAGE3 _j (x), R,
This can be realized by performing linear conversion on the data of each of G and B colors as a unit. In the next steps 326 and 328, normalization conditions for normalizing the image data by linear conversion are determined based on the data of the gray candidate points extracted from the film image data IMAGE3 _j (x).

That is, in step 326, R, R, and G of all gray candidate points finally extracted from each film image
The average density Dr, Dg, Db for each of G and B is calculated. In step 328, the film image data is set so that the average densities Dr, Dg, and Db of the gray candidate points in the image data after the normalization processing are all equal (Dr = Dg = Db).
A first normalization condition for normalizing IMAGE3 _j (x) (more specifically, a gain Ganma1 _j and an offset amount Offset1 _j , which are parameters of a linear conversion equation for performing normalization),
It is obtained by calculation for each of R, G, and B based on a specific component color (for example, G).

The normalization conditions for the normalization process are obtained as described above. If the number of gray candidate points extracted from each film image is small, for example, the average density Dr for each of the R, G, and B gray candidate points is determined. , Dg, and Db do not accurately represent the deviation of each of the R, G, and B colors in the relationship between the exposure amount at the time of shooting and the density on the image represented by the film image data IMAGE3 _j (x). There is. Therefore, even if the normalization process is performed using only the first normalization condition, the color balance may not be accurately corrected.

For this reason, in the first embodiment, based on the characteristic data FilmData _j (d), the characteristic data
The second normalization is performed such that a conversion equivalent to making the conversion curves of the conversion conditions for each of the R, G, and B colors represented by _j (d) substantially coincide (overlap) (in this case, linear conversion may be performed). condition (which is a parameter of the linear transformation formula gain Ganma2 _j, offset Offset2 _j) are set in advance are stored in advance in the characteristic data storage unit 144B. Next step 33
At 0, the second standardization condition corresponding to the film type of the photographic film to be processed is fetched.

In the next step 332, step 328
Parameter of the normalization condition calculated in step 330 and step 330
The parameters of the standardization condition fetched in are weighted and added according to the following equation (3) to calculate the parameters.

[0090] _{Ganma j = α 1 × Ganma1 j} + α 2 × Ganma2 j Offset j = α 1 × Offset1 j + α 2 × Offset2 j ... (3) In step 334, the film image data of a particular film image IMAGE3 _j (x) The parameters (gain Ganma _j , offset amount Offset) calculated in step 332 are applied to the captured film image data IMAGE3 _j (x).
_{Using j} ), a normalization process is performed for each of R, G, and B according to the following equation (4). This normalization processing corresponds to the normalization of image data described in claim 5 (more specifically, the normalization of image data described in claim 6).

IMAGE4 _j (x) = Ganma _j × IMAGE3 _j (x) + Offset _j (4) By the above-described normalization processing, the difference between the original exposure amount of the photographic film and the color density characteristics for each of R, G, and B Also, the color balance of the image to be processed (R, G,
It is possible to correct the deviation of the density of each B). Accordingly, image data in which the relationship between the exposure amount of each of the R, G, and B colors at the time of shooting and the density on the image represented by the image data is linear and substantially coincides with each other, ie, accurately represents the subject image at the time of shooting. Film image data IMAGE4 _j (x) can be obtained.

In the above-described normalization processing, based on the number of gray candidate points finally extracted from each film image,
The parameters of the first normalization condition obtained from the film image data (Ganma1 _j, Offset1 _j), the parameters of the second standard conditions determined from the characteristic data (Ganma2 _j, Offset
2 _j ) is weighted and the parameters (Ganma _j , O
ffset _j ), even when the number of gray candidate points extracted from each film image is small and the correction accuracy by the normalization process is estimated to be low, the weight for the parameter of the first standard condition is By reducing the size, the color balance of the image represented by the image data can be corrected with high accuracy.

In the next step 336, various image features such as the density of the film image are calculated based on the film image data IMAGE4 _j (x) after the normalization processing, and based on the calculated image features. The line CCD scanner 14 calculates reading conditions when performing the fine scan of the specific film image, and image data (fine scan image data) obtained by performing the fine scan of the specific film image with the line CCD scanner 14. ) Is determined. Note that the determined processing conditions of the image processing correspond to information (for example, frame number) for identifying a specific film image and are stored in the RAM 14.
8 is stored.

In step 338, it is determined whether or not the processing in steps 334 and 336 has been performed on all the film images recorded on the photographic film to be processed. If the determination is negative, the process returns to step 334, and steps 334 to 338 are repeated for each film image until the determination in step 338 is affirmative. If the determination in step 338 is affirmative, the process proceeds to step 340, where the film image data IMAGE4 after the normalization processing of each film image is performed.
_j (x) is transferred to the personal computer 158 via the pre-scan memory 135, and the image processing conditions for the fine scan image data of each film image are transferred to the personal computer 158, thus ending the setup calculation process.

Film image data IMAG of each film image
When the processing conditions of E4 _j (x) and the image processing are transferred, the personal computer 158 performs image verification processing. That is, in the prescanned image data processing unit 158A,
Based on the processing condition of image processing transfers from automatic set-up engine 144, an image processing equivalent to the image processing of the film image data image4 _j executed by the image processor 140 as an object the fine scan image data
(x) to generate simulation image data. Further, the image display unit 158 uses the fine scan image data after the image processor 140 executes the image processing based on the simulation image data generated by the pre-scan image data processing unit 158A to create a print. The displayed simulation image is displayed on the display 164.

When the simulation image is displayed on the display 164, the operator visually checks the simulation image, and determines whether or not the frame position determined by the auto setup engine 144 is appropriate and whether the image quality of the simulation image is appropriate ( That is, whether or not the processing conditions of the standard image processing calculated by the auto setup engine 144 are appropriate) is verified, and information representing the verification result is input via the keyboard 166.

When the frame position and the processing conditions for image processing are instructed with respect to the specific film image, the auto setup engine 144 executes the setup calculation processing described above for the specific film image. The processing corresponding to the input correction instruction is performed again, and the film image data IMAGE4 _j (x) reflecting the input correction instruction and the processing conditions of the recalculated image processing are transferred. As a result, the simulation image corrected according to the input correction instruction is displayed on the display 164 again.

By visually confirming the re-displayed specific simulation image by the operator, the operator can easily determine whether or not the content of the previously input correction information is appropriate. Then, when the operator inputs the information indicating the pass of the test, the image test process ends.

On the other hand, when the pre-scan for the photographic film is completed, the line CCD scanner 14 performs a fine scan for reading the photographic film for each film image. At the time of this fine scan, reading conditions for each film image are notified to the line CCD scanner 14 from the auto setup engine 144, and the line CCD scanner 14 reads each film image (fine scan) according to the notified reading conditions. Do.

The processing conditions for image processing for each film image are notified from the auto setup engine 144 to the image processor 140 when fine scan image data of each film image is input from the line CCD scanner 14. Image processor 14
0 performs image processing of the notified processing contents on the input fine scan image data of each film image.

Here, the offset calculation section 140B of the image processor 140 performs the offset correction processing according to the equation (1) using the offset correction value stored in the step 312 of the setup calculation processing described above.
The non-linearity correction unit 140C performs the non-linearity correction processing according to the equation (2) using the characteristic data FilmData _j (d) set as the conversion condition in step 306 of the setup calculation processing. Further, the image data normalizing unit 140D
Using the parameters (Ganma _j , Offset _j ) calculated in step 332 of the setup calculation process, a normalization process is performed according to equation (2). As described above, the fine scan image data is converted into image data that accurately represents a subject image at the time of shooting.

The fine scan image data input to the image processor 140 may be used in addition to the above-described image processing, in addition to the first image processing section 140A and the second image processing section 1A.
After various image processing is performed in 40E, the image data is output from the image processor 140 as output image data.
This output image data is used for recording an image on photographic paper in the laser printer unit 18, for displaying an image on the display 164, or for storing information in a memory card or the like via the expansion slot 174. Stored on the medium.

[Second Embodiment] Next, a second embodiment of the present invention will be described. Since the second embodiment has substantially the same configuration as the first embodiment, the same portions are denoted by the same reference numerals and description thereof will be omitted.

As shown in FIG. 9, the image processor 140 according to the second embodiment includes an offset correction unit 140
An image data normalizing unit 140D is arranged on the output side of B,
A nonlinearity correction unit 140C is arranged on the output side of the image data normalization unit 140D. Therefore, the image data subjected to the offset correction processing by the offset correction unit 140B of the image processor 140 is output to the image data normalization unit 14B.
After the normalization process is performed in 0D, the nonlinearity correction unit 14
Non-linearity correction is performed at 0C.

As shown in FIG. 5B, the characteristic data storage section 144 according to the second embodiment shows the relationship between the exposure amount of the photographic film and the density of the reference color (for example, G). Characteristic data determined according to the exposure-color density characteristics
FilmData (d) is stored. This characteristic data FilmDa
Also for ta (d), the characteristic data described in the first embodiment
Similarly to FilmData _j (d), the image data of the film image recorded on the photographic film is
(LogH)-Exposure of the same subject as the film image to a virtual photographic film having an exposure-color density characteristic equal to the linear portion of the color density (d) characteristic extended to an exposure region where the characteristic becomes non-linear. It shows a conversion condition for converting a density value so as to be substantially equal to virtual image data representing a virtual film image obtained by recording and developing (nonlinear corrective correction according to the present invention).

Next, the setup calculation processing according to the second embodiment will be described with reference to the flowchart of FIG.
Only parts different from the setup calculation processing according to the first embodiment will be described.

In the setup calculation processing according to the second embodiment, in the processing for each film image in steps 314 to 320, cutting out of the film image data IMAGE _j (x) (step 314) and offset correction processing (Step 316) only,
No nonlinearity correction processing is performed. Then, when the processing of the above-described steps 314 and 316 is performed on all the film images, the determination of step 320 is affirmed, and step 323 is performed.
Move to.

As is clear from the configuration of the image processor 140 described above, in the second embodiment, the film image data (IMAGE2 _j (x)) after the offset correction processing (ie, before the nonlinearity correction processing) is added to the image data. Then, normalization processing is performed. The relationship between the exposure amount of each of the R, G, and B colors at the time of shooting and the density on the image represented by the film image data IMAGE2 _j (x) is nonlinear. Therefore, the color balance of the image represented by the image data is made to substantially match the color balance of the subject image (the exposure amount at the time of photographing for each of the R, G, and B colors and the density on the image represented by the film image data IMAGE2 _j (x)). To make the relationship approximately the same)
It is necessary to convert data of component colors other than the reference color of IMAGE2 _j (x) under different conversion conditions for each density range.

Therefore, in step 323, gray candidate points are extracted from each film image over the entire density range, and in the next step 325, the three-color average density or reference color (for example, G) of each extracted gray candidate point is extracted. It is determined based on the density of each of the gray candidate points to which of the plurality of density areas belongs, and all the gray candidate points are classified into each density area, and the gray candidate points are classified into R, G, B The average densities Dr, Dg, and Db are calculated for each density range. And in step 327,
The average densities Dr, Dg, and Db for each density area in the image data after the normalization processing are all equal (for example, if the reference color is G, Dr and Db are equal to Dg based on Dg).
Thus, a normalization condition (conversion condition LUT _j (d)) for normalizing the film image data IMAGE2 _j (x) is obtained.

In the next step 329 and subsequent steps, normalization processing and non-linearity correction processing are sequentially performed on the data of each film image. That is, in step 329, the film image data IMAGE2 _j (x) of the specific film image is fetched, and the conversion condition LU of the normalization processing obtained in step 327 is applied to the fetched film image data IMAGE2 _j (x).
Using T _j (d), normalization processing is performed for each of R, G, and B in units of data of each pixel according to the following equation (5).

IMAGE3 _j (x) = LUT _j (IMAGE2 _j (x)) (5) By the above-described normalization processing, the difference between the original exposure amount-color density characteristics of the photographic film for each of R, G, and B, , The color balance (R, G,
The deviation of the density balance for each B) is corrected.

In the next step 331, the characteristic data FilmData (d) fetched in the previous step 304 is used for the film image data IMAGE3 _j (x) after the normalization processing, and the individual image data is obtained according to the following equation (6). The nonlinearity correction processing is performed using pixel data as a unit. This step 331 also corresponds to the non-linearity correction according to claim 1 (correction means according to claim 8).

IMAGE4 _j (x) = FilmData (IMAGE3 _j (x)) (6) The film image data IMAGE3 _j (x) is exposed at the time of shooting for each of the R, G, and B colors by the normalization processing in step 329. Since the relationship between the amount and the density on the image represented by the film image data IMAGE3 _j (x) is approximately the same, the R, G, and B data are calculated as shown in equation (6) as the nonlinearity correction processing. By performing the conversion under the same conversion conditions, the influence of the non-linearity of the exposure-color density characteristic of the photographic film to be processed is removed for each of the R, G, and B colors. As a result, the image data in which the relationship between the exposure amount of each of the R, G, and B colors at the time of shooting and the density on the image represented by the image data is linear and substantially coincides with each other, that is, the subject image at the time of shooting can be accurately determined. Film image data IMAGE4 _j (x) to be obtained.

When the fine scan image data is input to the image processor 140 according to the second embodiment, the offset calculation unit 1 of the image processor 140
40B performs an offset correction process according to equation (1) using the offset correction value stored in step 312 of the setup calculation process. Also, the image data normalizing unit 14
0D uses the conversion condition LUT _j (d) of the normalization process obtained in step 327 of the setup operation process, and performs the normalization process according to equation (5). Further, the nonlinearity correction unit 14
0C uses the characteristic data FilmData (d) set as the conversion condition in step 306 of the setup calculation process,
The nonlinearity correction processing is performed according to the equation (6). As described above, the fine scan image data is converted into image data that accurately represents a subject image at the time of shooting.

In the above description, the characteristic data FilmData _j (d)
Alternatively, the mode in which FilmData (d) is set and stored in advance has been described. However, the present invention is not limited to this, and data representing the exposure-color density characteristic itself of the photographic film is stored and the setup calculation The characteristic data may be obtained at the time of processing.

In the above description, the offset correction is performed on the film image data IMAGE _j (x). However, the present invention is not limited to this.
The characteristic data may be corrected so that the conversion characteristic represented by ta _j (d) or FilmData (d) is shifted in parallel to the density axis corresponding to the input side.

In the above description, a photographic film was described as an example of the photosensitive material according to the present invention. However, the present invention is not limited to this. By reading an image exposed and recorded on another photosensitive material such as photographic paper. The present invention is also applicable to the case where correction is performed on the obtained image data, and the non-linearity of the photoelectric conversion characteristic is obtained for the image data obtained by performing imaging using the optical sensor having the non-linear photoelectric conversion characteristic. It is also possible to apply it in the case of correction and the like.

[0118]

As described above, according to the first and eighth aspects of the present invention, characteristic data is stored for each type of photosensitive material, and the characteristic data is stored based on the type of photosensitive material to be processed. Data is selected, and based on the selected characteristic data, the read image data of the image to be processed extends the linear part of the exposure-color density characteristic of the photosensitive material to be processed to an exposure range where the characteristic becomes nonlinear. Non-linearly with respect to the read image data so as to be substantially equal to virtual image data representing a virtual image obtained by exposing and recording the same subject as the processing target image on a virtual photosensitive material having characteristics equal to Image data obtained by reading an image that has been exposed and recorded on a photosensitive material and visualized by a development process, an image that accurately represents the subject image at the time of exposure recording Can be acquired over data, it has an excellent effect that.

According to a second aspect of the present invention, in the first aspect, a conversion condition for converting the density of an image recorded on a photosensitive material into the density of an image recorded on a virtual photosensitive material is used as characteristic data. The non-linearity correction is performed by converting the read image data according to the conversion condition represented by the characteristic data using the data represented by the characteristic data. Having.

According to a third aspect of the present invention, in the second aspect of the invention, the conversion condition is determined so that the gradient of the conversion characteristic is equal to or less than a predetermined maximum value. Has the effect that the image data can be prevented from being converted such that the image represented by has an undesired tone in which the graininess of the film is excessively emphasized.

According to a fourth aspect of the present invention, in the first aspect of the invention, prior to the execution of the non-linearity correction, the density of the film base of the photographic film to be processed is detected, and the detected density of the film base is determined. The read image data or the characteristic data of the photographic film is corrected in advance so as to substantially match the density of the film base defined by the characteristic data of (1). From the data, there is an effect that the influence of the fluctuation of the film base density of the photographic film caused by the fluctuation of the developing conditions can be excluded.

According to a fifth aspect of the present invention, in the first aspect of the present invention, non-linearity correction and normalization of image data for correcting the density balance for each component color of the image data based on at least the read image data are performed. Since it is performed on the previously read image data or the image data obtained by performing the non-linearity correction, in addition to the above-described effects, the density for each component color of the image data representing the subject image at the time of exposure recording This has the effect that the balance can be made appropriate.

According to a sixth aspect of the present invention, a weight for the normalization condition based on the read image data and the weight for the normalization condition based on the characteristic data is determined based on the result of analyzing the processing target image using the read image data. The normalization condition based on the read image data and the normalization condition based on the characteristic data are weighted in accordance with the weighted values to normalize the image data. Even in the case of image contents in which the correction accuracy is significantly reduced when the density balance of each color is corrected, it is possible to avoid that the correction accuracy of the density balance of each component color is significantly reduced, There is an effect that image data accurately representing a subject image at the time of exposure recording can be acquired from the read image data.

According to a seventh aspect of the present invention, in the invention of the sixth aspect, as the analysis of the image to be processed, data of pixels whose hue on the subject image is estimated to be an achromatic color is extracted from the read image data. Since the weight for each of the read image data and the characteristic data is determined based on the number of extracted pixels, in addition to the above effects, the density balance of each component color of the image data is always corrected with high correction accuracy. Has the effect of being able to

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a digital laboratory system according to an embodiment.

FIG. 2 is an external view of a digital laboratory system.

FIG. 3 is a block diagram illustrating a schematic configuration of an image processing unit.

FIG. 4 is a block diagram illustrating functions of an auto setup engine and a personal computer of an image processing unit according to the first embodiment, divided into blocks, and showing an internal configuration of an image processor.

FIG. 5A is a diagram illustrating an example of a conversion characteristic represented by characteristic data according to the first embodiment, and FIG. 5B is a diagram illustrating an example of a conversion characteristic represented by characteristic data according to the second embodiment;

6A is a diagram illustrating an example of an exposure amount-coloring density characteristic of a photographic film to be processed, and FIG. 6B is a diagram illustrating an example of an exposure amount-coloring density characteristic of a virtual photographic film.

FIG. 7 is a flowchart illustrating a setup calculation process according to the first embodiment.

FIG. 8 is a diagram illustrating an example of an achromatic condition for extracting a gray candidate point.

FIG. 9 is a block diagram illustrating functions of an auto setup engine and a personal computer of an image processing unit according to a second embodiment, divided into blocks, and showing an internal configuration of an image processor.

FIG. 10 is a flowchart illustrating a setup calculation process according to the second embodiment.

[Explanation of symbols]

 10 Digital Lab System 140 Image Processor 140B Offset Correction Unit 140C Nonlinearity Correction Unit 140D Image Data Normalization Unit 144 Auto Setup Engine 144A Setup Operation Unit 144B Characteristic Data Storage Unit

Continued on the front page F-term (reference) 2H110 BA17 BA18 BA19 CB32 CB35 CB41 CB44 CB76 5C062 AB03 AB17 AB42 AC21 AC22 AE03 BA00 5C077 LL19 MM20 MP08 NN02 NP01 PP15 PP32 PP37 PP41 PP43 PP47 PQ08 PQ18 PQ20 PQ07 SS0606 LA31 LB01 MA04 NA03 PA03 PA05 PA08

Claims (8)

[Claims] 1. Characteristic data determined according to the exposure amount-color density characteristic of a photosensitive material is stored for each type of photosensitive material, and corresponding to the type of photosensitive material to be processed based on the type of photosensitive material to be processed. Selected characteristic data to be read, and based on the selected characteristic data, read image data obtained by reading a processing target image that has been exposed and recorded on the processing target photosensitive material and visualized by a development process, and the readout image data is the photosensitive material. Exposure recording and development of the same subject as the image to be processed on a virtual photosensitive material having an exposure-color density characteristic equal to the linear portion of the exposure-color density characteristic extended to an exposure region where the characteristic becomes nonlinear. An image data correction method for performing non-linearity correction on the read image data so as to be substantially equal to virtual image data representing a virtual image obtained by performing the processing. 2. The characteristic data is data representing conversion conditions for converting the density of an image recorded on the photosensitive material into the density of an image recorded on the virtual photosensitive material.
2. The image data correction method according to claim 1, wherein the nonlinearity correction is performed by converting the read image data according to a conversion condition represented by the characteristic data. 3. The image data correction method according to claim 2, wherein the conversion condition is determined such that a gradient of the conversion characteristic is equal to or less than a predetermined maximum value. 4. The photosensitive material is a photographic film, and prior to execution of the nonlinearity correction, a density of a film base of the photographic film to be processed is detected, and the detected density of the film base and characteristics of the photographic film are detected. 2. The image data correction method according to claim 1, wherein the read image data or the characteristic data of the photographic film is corrected in advance according to a difference from a film-based density defined by the data. 5. A method for normalizing image data for correcting a density balance for each component color of image data based on at least the read image data, the method comprising: reading the read image data before performing the non-linearity correction; 2. The image data correction method according to claim 1, wherein the method is performed on image data obtained by performing. 6. A characteristic data determined according to an exposure amount-color density characteristic of a photosensitive material is stored for each type of the photosensitive material, and the processing object exposed to and recorded on the processing target material and visualized by a developing process. Analyzing the processing target image using read image data obtained by reading an image, and determining weights for the normalization based on the read image data and the normalization based on the characteristic data based on the result of the analysis. Image data correction for performing normalization based on the read image data and normalization weighting based on the characteristic data in accordance with the determined weight to correct the density balance of each component color of the image data; Method. 7. As the analysis of the processing target image, data of pixels whose hue on the subject image is estimated to be achromatic is extracted from the read image data, and the weight is determined based on the number of extracted pixels. 7. The method according to claim 6, wherein the determination is performed. 8. A storage means for storing, for each type of photosensitive material, characteristic data determined according to the exposure amount-coloring density characteristic of the photosensitive material, and the storage means for storing the characteristic data based on the type of photosensitive material to be processed. Selecting means for selecting characteristic data corresponding to the photosensitive material to be processed among the characteristic data being processed; reading means for reading an image to be processed which is exposed and recorded on the photosensitive material to be processed and visualized by a development process; Based on the selected characteristic data, the read image data obtained by reading the image to be processed by the reading means changes the linear part of the exposure-color density characteristic of the photosensitive material to an exposure range where the characteristic becomes nonlinear. A virtual image obtained by exposing and recording the same subject as the image to be processed on a virtual photosensitive material having an exposure amount-coloring density characteristic equal to To be substantially equal to the virtual image data representing an image processing apparatus including a correction unit for performing nonlinear correction on the read image data.