JPH10290368A - Contour emphasis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the printed image quality from declining by adding contour emphasis signals prepared based on image signals to the image signals obtained by picking up the image of a silver film or the like, detecting conditions for inviting the image quality decline by the particles of the silver film of visibly outputted images and reducing the contour emphasis signals. SOLUTION: A control part 60 judges whether or not the particle size of the silver film is read over plural pixels and the particle size is enlarged to a visible size and printed by a visible resolution based on input kind information, printing information, printer kind information, film information and information for indicating the resolution at the time of photographing from a data input part 62. When judgement matches, a parameter file storing a lookup table provided with a filter coefficient for reducing contour emphasis from normal contour emphasis is selected and a contour correction processing part 58 is controlled. Thus, the contour emphasis of the silver film particle is reduced and the image quality degradation accompanying the contour emphasis is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outline emphasizing method, and more particularly to a method for generating an outline emphasizing signal based on an image signal obtained by imaging a developed silver halide film, and applying the outline emphasizing signal to the image signal. The present invention relates to a contour emphasizing method for emphasizing a contour of an image that is visually output by adding.

[0002]

2. Description of the Related Art Heretofore, there has been proposed a method in which a developed silver halide film is picked up by a high-resolution image sensor, and the picked-up film image is printed at a high magnification. On the other hand, in order to obtain a sense of sharpness of a reproduced image, an image signal obtained by creating an outline emphasis signal based on an image signal obtained by imaging a subject such as a film image, and adding the outline emphasis signal to the image signal There is known an image reproducing apparatus for displaying a film image on a TV monitor or the like based on an image.

[0003]

By the way, when a developed silver halide film is picked up by a high-resolution image sensor, and the picked-up film image is enlarged and printed at high magnification,
Grain-like particles may be discerned in the print image due to the graininess of the silver halide film. In such a case, if the contour enhancement processing of adding the contour enhancement signal to the image signal is performed, the contour of the grain-like particles is also enhanced, and the particles are conspicuous, so that the image quality of the print image is rather deteriorated.

[0004] The present invention has been made in view of such circumstances, and by preventing the contour enhancement processing that increases the effect of the graininess of a silver halide film from being performed, the image quality of a printed image can be reduced. It is an object of the present invention to provide an image enhancement method that can prevent the image enhancement.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an image processing method which comprises developing a contour of a silver halide film or a printed matter printed using the silver halide film. In an edge enhancement method for creating an enhancement signal and adding the edge enhancement signal to the image signal, the edge enhancement method for enhancing the edge of the image that is visibly output, wherein the silver salt of the image that is visibly output is It is characterized in that a condition that causes image quality deterioration due to film particles is detected, and when the condition is detected, the contour emphasis signal is reduced. The detection of the condition is performed based on a resolution at the time of photographing the silver halide film or the printed matter, and a resolution and an enlargement ratio of an image that is visibly output.

[0006] Thus, when particles of the silver halide film are discerned in the visually output image, the contour enhancement of the particles is reduced, so that it is possible to prevent the image quality from being deteriorated due to the contour enhancement. Further, the present invention, when reducing the contour emphasizing signal, changes the coefficient or size of a spatial filter for creating the contour emphasizing signal, and reduces the contour emphasizing signal for the image signal indicating the particles of the silver halide film. It is characterized by.

According to another aspect of the present invention, an outline emphasis signal is created based on an image signal obtained by imaging a developed silver halide film or a printed matter printed using the silver halide film. In the contour emphasizing method for emphasizing the contour of an image that is visibly output by adding a contour emphasizing signal after performing a coring process for removing a noise signal from the contour emphasizing signal to the image signal, An image that can be output is detected under conditions that cause image quality degradation due to the silver halide film particles, and when the conditions are detected, the signal range removed by the coring process is widened to reduce the silver halide film particles. It is characterized in that the edge enhancement signal for the image signal shown is reduced.

That is, since the level of the edge enhancement signal due to silver halide film particles is small, when a condition that causes image quality deterioration due to silver halide film particles is detected, the signal range to be removed by coring processing is increased, and the silver halide film is removed. An edge emphasis signal for an image signal indicating film particles is removed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a contour emphasizing method according to the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 is a configuration diagram showing an embodiment of an image processing system to which the present invention is applied.

[0010] As shown in FIG.
Image input unit 10, image processing unit 20, and image output unit 30
It is composed of The image input unit 10 includes image input devices such as various scanners 10A and digital files 10B. The apparatus shown in FIGS. 1A and 1B is, for example, a frame image of a film compatible with the new photo system (APS), 135 mm.
A film scanner that reads a frame image of the film and outputs an image signal indicating the read frame image;
The device C indicates a scanner that reads a print (photograph) printed using a silver halide film and outputs an image signal indicating the read print. Also,
The digital file 10B is a device for outputting a digital image recorded in advance.

The image input unit 10 outputs film information (film sensitivity, negative / positive, film size, film type) and information indicating the resolution at the time of photographing (scan density, photographing magnification, etc.). In addition, the film information
The information used for estimating the particle size of the silver halide film and indicating the resolution at the time of photographing is based on the fact that the estimated particle size corresponds to a plurality of pixels (for example, 2 × 2,
3 × 3).

The image processing unit 20 includes a contour correction processing unit 20
A and 20B and other image processing units (not shown). The image processing unit 20 includes the various scanners 10A.
Various image processes are performed on the image signal input from the digital file 10B and the digital image signal input from the digital file 10B, and the image signal is output to the image output unit 30. By the way, the contour correction processing section 20A and the contour correction processing section 20 shown in FIG.
A processing unit B performs an outline emphasis process on the image signals input from the scanner 10A and the digital file 10B, respectively. These contour correction processing units 20A and 20B
The degree of contour enhancement is determined based on whether or not the particle size is imaged over a plurality of pixels, editing information (enlargement / reduction of the image) of the output image, characteristics (print density) of the output destination printer 30A, and the like. adjust. The details will be described later.

The image output section 30 includes various printers 30A and digital files 30B. FIG.
Are printers of different types (for example, different printing methods and different printing densities (resolutions)). The digital file 30B records a digital image signal output from the image processing unit 20. As shown in the figure, when outputting the image signal input from the image input unit 10 to the printer 30A of the image output unit 30, the image processing unit 20 performs the outline enhancement processing via the outline correction processing units 20A and 20B. And the image signal is converted to a digital file 3
0B, since it is not known how this image signal will be used later, the contour correction processing unit 20A,
This image signal is transferred to the digital file 30 without passing through the digital file 30B.
B, so that processing is kept to a minimum.

FIG. 2 is a block diagram showing an embodiment of a film image processing apparatus to which the above-mentioned image processing system is applied. As shown in the figure, the film image processing apparatus includes an imaging unit 50, a file card reading unit 52, a color / gradation processing unit 54, an enlargement / reduction processing unit 56, an outline correction processing unit 58, a control unit 60, And a data input unit 62. Note that the imaging unit 50 corresponds to the scanner 10A in FIG. 1, and the file / card reading unit 52 corresponds to the digital file 10B in FIG.

Each frame image recorded on the film is picked up by the image pick-up unit 50, and the image signals of the picked-up frame images are sequentially output to the color / gradation processing unit 54. Also,
When each frame image is recorded in advance as a digital image signal on a recording medium such as a file or a card, each frame image is read from the file / card reading unit 52 and the color / color image is read.
It is output to the gradation processing unit 54.

The color / gradation processing unit 54 adjusts the image signal input from the image pickup unit 50 or the file card reading unit 52 such as white balance, black balance, and γ correction, and enlarges / reduces the image signal. Output to the unit 56. By the way, the control unit 60 includes information indicating an input device for inputting an image signal (hereinafter, referred to as input type information), print size (enlargement / reduction magnification) for each frame image to be output to the printer, and trimming information (hereinafter, referred to as input type information). , Print information) and information of a printer to be used (print density (dpi), etc.) (hereinafter, referred to as printer type information) are input from the data input unit 62. Further, as described above, film information used for estimating the particle size of the silver halide film and information indicating the resolution at the time of photographing are also input to the control unit 60.

Then, based on the information, the control unit 60 reads the particle size across a plurality of pixels and the particle size can be visually checked (for example,
(1 to 2 cycles / mm) and determines whether or not printing is performed with a visible resolution, and a parameter file used for contour enhancement is selected based on the determination result. still,
Different types of contour enhancement processing can be performed depending on the selected parameter file. The control unit 60 outputs a selection signal indicating the selected parameter file to the contour correction processing unit 58. The details will be described later.

The enlargement / reduction processing unit 56 performs enlargement / reduction processing on the input image signal based on the enlargement / reduction magnification input from the control unit 60, and outputs this image signal to the contour correction processing unit 58. The contour correction processing section 58 selects an appropriate parameter file according to the selection signal input from the control section 60, performs contour enhancement processing adapted to the input image signal using the parameter file, and outputs this image signal to the printer.

Next, the outline emphasis processing of the outline correction processing section 58 will be described in detail. FIG. 3 is a classification table of the parameter file selected by the control unit 60 as described above. As shown in the figure, when an image signal is printed out to a printer, a parameter file is used to perform outline emphasis processing, but when digitally output to a digital file, the parameter enhancement processing is not performed. Do not use files.

When the image signal is printed out to a printer, when the image signal is input from a scanner to a scanner,
The parameter files to be used when digitally inputting from a digital file are classified, and the parameter files to be used are also classified according to the type of printer to be output. Furthermore, they are classified into five types of parameter files according to the enlargement / reduction magnification of the enlargement / reduction processing unit 56. Note that the index in the enlargement / reduction magnification indicates the enlargement / reduction magnification when all the film images recorded on the film are reduced to one sheet and index printed.

Here, each parameter file shown in FIG. 3 stores a look-up table (LUT) indicating filter coefficients of a spatial filter for performing different edge enhancement. Then, among the parameter files set according to the input type, the printer type, and the enlargement / reduction ratio, at least the input type, the printer type, the enlargement / reduction ratio, etc. The granular size is enlarged to a size that can be seen,
In addition, the parameter file corresponding to the condition for printing at a visible resolution stores an LUT having a filter coefficient for reducing the contour enhancement from the normal contour enhancement.

The control unit 60 includes an input type, a printer type,
A selection signal for selecting one parameter file from the parameter files classified as described above based on the enlargement / reduction ratio and the like is output to the contour correction processing unit 58. The contour correction processing unit 58 sets data of a parameter file corresponding to the selection signal from the parameter files shown in FIG. 3 based on the selection signal input from the control unit 60, and uses the set data. Perform contour enhancement processing. The control unit 60 determines whether or not the particle size is read across a plurality of pixels as described above. If the particle size is not read across a plurality of pixels, Does not perform edge enhancement that emphasizes particles, and therefore selects a parameter file that performs normal edge enhancement.

FIG. 4 is a block diagram showing an embodiment of the contour correction processing section 58. As shown in the figure, the contour correction processing unit 58 includes a calculation unit 64 and a memory 66. As shown in the figure, the arithmetic unit 64 is composed of spatial filters 68A, 68B, 68C for each of R, G, B, and coring processing units 70A, 70B, 70C.

The spatial filters 68A, 68B, 68C are:
It has 5 × 5 filter coefficients, and the spatial arrangement of 5 × 5 image data as shown in FIG.
Are arranged as shown in FIG. And FIG.
A ₁₁ of a 5 × 5 pixel adjacent to the target pixel a shown in FIG.
From A to A ₅₅ (where A ₃₃ is the pixel of interest a),
5 15 filter coefficients for which the filter coefficients (a vertically symmetrical in 5 × 5 shown in (B) is from C ₁ to C ₁₅
), And computes the operation result value (filter output) a ′ with the coring processing units 70A, 70B, 70A.
Output to C.

Coring units 70A, 70B, 70C
Receives the pixel value of the pixel of interest a and the filter output a 'of the spatial filter, converts the filter output a' by the function f shown in FIG. A value (output pixel value) A obtained by adding the pixel value is output. That is, assuming that a ″ = f (a ′), A = a + a ″ is output.

The spatial filter 68 of the arithmetic unit 64
The filter coefficients of A, 68B, and 68C and the look-up table for performing the coring processing of the coring processing units 70A, 70B, and 70C are recorded in the memory 66 in advance as the above-described parameter file. FIG.
FIG. 3 is a diagram showing a data configuration of a parameter file in FIG. As shown in FIG.
G, the spatial filter 68A for each B, 68B, and the data from the filter coefficients C ₁ to 68C up to C _15, R, G, coring processing section 70A of each B, 70B, with respect to 70C, the pixel value of the target pixel a Spatial filters 68A, 68B, 68
The output pixel value A data (lookup table) corresponding to the value of the filter output a 'of C is arranged in order.

The operation unit 64 reads a parameter file indicated by the selection signal input from the control unit 60 from a plurality of parameter files recorded in the memory 66, and sets filter coefficients in the spatial filters 68A, 68B, 68C. Coring processing units 70A, 70B, 7
A look-up table is set in the 0C section, the above-described filtering process and coring process are performed, and an image signal obtained by adding the contour emphasis signal is output.

In this embodiment, when a condition that causes image quality deterioration due to silver halide film particles is detected, contour enhancement is reduced from a plurality of spatial filters having different filter coefficients, compared to normal contour enhancement. Although the filter is selected and the contour enhancement of the particle is reduced, the present invention is not limited to this, and a filter that reduces the contour enhancement of the particle may be selected from a plurality of spatial filters having different sizes. Also,
The gain of the edge enhancement signal may be controlled without using a plurality of spatial filters.

Further, the coring processing units 70A, 70B and 70C of this embodiment include the spatial filters 68A,
When the signals input from 8B and 68C are within a predetermined dead band width w as shown in FIG. 6, the signals are regarded as noise and are not output, but the dead band width w is changed.
Thus, an edge enhancement signal that enhances the granular noise of the silver halide film may not be output. That is,
Since the level of the contour emphasis signal generated by the grain noise component of the silver halide film is small, when a condition that causes image quality deterioration due to the grain of the silver halide film is detected, at least the level of the contour emphasis signal generated by the grain noise component is detected. However, the width w of the dead zone is changed so as to enter the dead zone of the coring processing sections 70A, 70B and 70C, so that the granular noise of the silver halide film is not enhanced by the edge enhancement signal.

When a condition that causes image quality deterioration due to silver halide film particles is detected, a process of reducing the contour emphasizing signal using a spatial filter or the like is performed, and the contour corresponding to the granular noise as described above is processed. The process of removing the emphasis signal by the coring process may be used together, or only one of the processes may be performed.

[0031]

As described above, according to the contour emphasizing method according to the present invention, when a condition for distinguishing particles of a silver halide film is detected in a visually output image, the contour emphasis of the particles is detected. Is reduced or eliminated, so that it is possible to prevent the image quality from deteriorating due to the contour enhancement of the granular noise.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image processing system to which the present invention is applied.

FIG. 2 is a configuration diagram showing an embodiment of a film image processing apparatus.

FIG. 3 is a classification table of a parameter file.

FIG. 4 is a configuration diagram illustrating an embodiment of a contour correction processing unit.

FIG. 5 is a diagram showing a spatial arrangement of image data and filter coefficients.

FIG. 6 is a diagram showing functions used for coring processing.

FIG. 7 is a diagram showing a data configuration of a parameter file.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Image input part 10A ... Scanner 10B ... Digital file 20 ... Image processing part 20A, 20B ... Contour correction processing part 30 ... Image output part 30A ... Printer 30B ... Digital file 50 ... Imaging part 52 ... File card reading part 54 ... Color / gradation processing unit 56 ... Enlargement / reduction processing unit 58 ... Contour correction processing unit 60 ... Control unit 62 ... Data input unit 64 ... Calculation unit 66 ... Memory 68A, 68B, 68C ... Spatial filter 70A, 70B, 70C ... Core Ring processing unit

Claims (4)

[Claims] 1. A contour enhancement signal is created based on an image signal obtained by imaging a developed silver halide film or a printed matter printed using the silver halide film, and the contour enhancement signal is converted to the image signal. In the contour emphasizing method of emphasizing the outline of an image that is visually output by adding, a condition that causes a deterioration in image quality of the image that is visually output and that is caused by particles of the silver halide film is detected, and Wherein the edge enhancement signal is reduced when the is detected. 2. A contour enhancement signal is created based on an image signal obtained by imaging a developed silver halide film or a printed matter printed using the silver halide film, and the contour enhancement signal is converted to the image signal. In the contour emphasizing method of emphasizing the outline of an image that is visually output by adding, a condition that causes a deterioration in image quality of the image that is visually output and that is caused by particles of the silver halide film is detected, and Is detected, the coefficient or size of a spatial filter for creating the contour enhancement signal is changed to reduce the contour enhancement signal for the image signal indicating the particles of the silver halide film. 3. An outline emphasis signal is created based on an image signal obtained by imaging a developed silver halide film or a printed matter printed using the silver halide film, and a noise signal is removed from the outline emphasis signal. By adding a contour emphasizing signal after performing coring processing to the image signal, a contour emphasizing method of emphasizing a contour of an image that is output to be visible, wherein the image that is output to be visible is A condition that causes image quality deterioration due to the silver halide film particles is detected.When the condition is detected, a signal range to be removed by the coring process is widened, and a contour enhancement signal for an image signal indicating the silver halide film particles is generated. A contour emphasizing method characterized by reducing. 4. The method according to claim 1, wherein the detection of the condition is performed based on a resolution at the time of photographing the silver halide film or the printed matter, and a resolution and an enlargement ratio of an image which is visually output. One, two or three edge enhancement methods.