JPH0579972B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a device for displaying the main image of a color original on a monitor, which is used in a photo printing device, a preliminary negative verification device for photo printing, etc. It is.

[Conventional technology]

In general, in color originals such as color negative film and color positive film, in addition to frames with an appropriate amount of negative image exposure, there are also frames with negative images that are extremely underexposed, and negative images that are extremely overexposed. This includes frames such as , frames with high contrast of negative images, etc. Even with such negative images, during photo printing, the blue exposure, green exposure, and red exposure are controlled individually so that the printed photo has the appropriate color balance and density. . A common exposure control method is the LATD method, which measures the average transmitted luminance (LATD) of the screen for each color and controls the exposure amount of each color according to this LATD.

A normal color original image includes not only the intentionally photographed part (the main image) but also the background image located behind it. Most of these main images are
Since it is a person's face, if the density and color balance of this part are good, the printed photo is often considered to have a good finish. By the way, as mentioned above
When using LATD, the exposure is controlled so that the integral of each color is finished as gray, but this empirical rule holds true for background images containing landscapes, etc. Therefore,
With the LATD method, the main image may not produce a good finish depending on the scene.

In order to solve the problems of this LATD method,
Detects skin color in a positive image from the original color image,
There is a known method of controlling the printing exposure so that this area has a desirable flesh color on the printed photograph (for example, US Pat. No. 4,176,946). There is also known a device that manually specifies a main image, measures the image characteristics of this main image, and corrects the exposure amount by LATD (Japanese Patent Publication No. 55-29412).

[Problem that the invention seeks to solve]

The above-mentioned system that automatically detects skin-tone areas may misidentify this as a person's skin if the original color image contains a wall or other object that resembles a person's skin color, or the film characteristics may change over time. Gray can sometimes be mistaken for skin color due to changes in color or the shooting light source, but conventional devices have not been able to effectively deal with such misidentifications. In addition, in the method of specifying the main image by manual operation, it is necessary to specify the main image for each frame, which causes a problem that the operation is troublesome.

[Means for solving problems]

In order to solve the above problems, the present invention provides means for measuring the three-color density of each point of a color original image, a storage means for storing data defining a skin color range in a positive image, and a storage means for storing data defining a skin color range in a positive image. a determining means for comparing the measured value with the data in the storage means to determine whether each measurement point is a skin color; an image displaying means for displaying the color original image on a monitor; The image display apparatus is provided with a control means for controlling the image display means and causing the image display means to display a skin-colored area in a manner that is distinguishable from others.

That is, the present invention measures the three-color density of each point of a color original image, and determines whether each measurement point is a skin color by referring to data that defines the skin color range in a positive image. According to the determination result, the corresponding portion of the image displayed on the monitor is displayed in a distinguishable manner.

In addition to providing the three-color density measuring means and the image display means for a monitor independently, it is preferable that some of them be used in common. For example, a color TV camera may be used, the obtained three-color video signals may be sent to an image display means for display on a monitor, and three-color density signals may be created from the three-color video signals. Further, as the image display means, a CRT or a liquid crystal display device or the like is used. These image display means should preferably be capable of color display, but may also be of black and white display in order to reduce costs.

The operator observes the image display means to confirm whether the automatic judgment is correct, and if a judgment error has occurred, manually specifies the skin color portion and corrects the display. This manual specification can be performed using a keyboard, touch panel sensor, light pen, mouse, etc. This automatically determined or manually specified skin color portion is recognized as the main image and used during exposure calculation. As a result, the exposure amount is determined so that the main image is well-finished on the printed photograph.

Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

FIG. 1 shows an example of a photographic printing apparatus embodying the present invention. White light emitted from a white light source 10 passes through a diffusion tube 11 and a negative carrier 12, reaches a color original image, for example, a color negative film 13 set at a printing position, and illuminates it from below. The diffusion tube 11 is composed of a rectangular tube 14 whose inner surface is formed into a mirror surface, and two diffusion plates 15 fixed to both ends of the rectangular tube 14. This diffusion tube 11
A cyan filter 16 for adjusting the red component of the illumination light, a magenta filter 17 for adjusting the green component, and a yellow filter 18 for adjusting the blue component are provided between the and the white light source 10. It is located. The filter adjustment unit 19 adjusts the insertion amount of each color filter 16 to 18 into the optical path 20, depending on the calculation result of an exposure calculation formula described later. For example, if the amount of cyan filter 16 inserted is increased, the red component of the illumination light will be reduced, and the amount of red exposure will be reduced. The color negative film 13 is pressed down from above by a mask 21 operated by a solenoid (not shown) during photographic printing.

A lens 24 is disposed above the color negative film 13, and a color negative image is formed on a color photographic paper 26 while the shutter 25 is open. The shutter drive unit 27 is configured to drive the shutter 25
is opened for a certain period of time to give a standard exposure time. Further, when printing of one frame of the color photographic paper 26 is completed, the exposed portion is wound onto the take-up reel 28, and at the same time, the unexposed portion is pulled out from the supply reel 29.

A mirror 32 is pivotally disposed in the optical path 20, and is tilted at 45 degrees with respect to the optical path 20 as shown by the solid line during monitor display, and is retracted to the position shown by the two-dot chain line during photo printing. The light reflected by this mirror 32 passes through a lens 33 and then reaches a half mirror 34. The light transmitted through this half mirror 34 is incident on a sensor unit 35, and the light reflected downward is incident on a color TV camera 36.

The sensor unit 35 is composed of a lens 37, a color filter 38, and an image sensor 39, and receives three color signals (red, green, blue) of each pixel of a color negative image, either independently or in a mixed manner. Output in the state. image sensor 3
The trichromatic signal taken out from the A/D converter 4
0 is converted into a digital signal, and then a logarithmic converter 4
1, it is converted to a concentration signal at I/O port 4.
2 to the microcomputer 43. In this example, in order to reduce costs, one image sensor is used to extract the three-color signals of each pixel (measurement point), but instead of this, three color signals of red, green, and blue are used. An image sensor may also be used. In addition, color TV camera 3
If the color video signal output from 6 is used, the sensor unit 35 can be omitted.

As is well known, the microcomputer 43 includes an I/O port 42, a CPU 44, a RAM 45,
It is composed of a ROM 46, and performs exposure amount calculation and control of various parts, which will be described later. The RAM45
separates the captured color density signals for each color and stores them in frame memory sections 45a to 45c, respectively.

The color TV camera 36 captures a color negative image and outputs a video signal. This video signal is converted into a positive image video signal by a negative/positive converter 48 and then sent to a controller 49. This controller 49 is a color CRT50
At the same time, a positive image 51 is displayed on the display screen, and a signal from the microcomputer 43 is inputted so that the skin-colored part of the automatically determined positive image, that is, the main image, can be distinguished from the non-skin-colored part, that is, the background image. , the skin-tone area is displayed with high brightness.

When automatically detecting skin-colored areas, walls, etc., may be mistakenly recognized as skin-colored areas. In this case, it is necessary to manually specify the skin color portion. Therefore,
A position specifying means, for example, a light pen 53, is provided for observing the positive image 51 and specifying a skin color portion. This light pen 53 is a color CRT5
When the point designated as 0 lights up, it is photoelectrically converted and a signal is sent to the position detection section 52. Since the position information from the controller 49 is input to the position detection section 52, when a signal from the light pen 53 is generated, the coordinate position on the color CRT 50 is sent to the microcomputer 43. In addition to a light pen, a touch panel sensor, joy stick, track ball, XY cursor, etc. can be used as a position specifying means.

The keyboard 55 includes a numeric keypad, input keys 56 for density and color correction, and a reset key 57.
A burning start key 58 is provided. The reset key 57 is operated when a skin-colored portion is displayed on the color CRT 50 even though there is no skin-colored portion.

FIG. 2 shows an image sensor.
The image sensor 39 includes a blue photoelectric conversion section 63 with a blue filter arranged on the light receiving surface, a green photoelectric conversion section 64 with a green filter arranged on the light receiving surface, and a red photoelectric conversion section 6 with a red filter arranged on the light receiving surface.
5 are alternately arranged in a matrix at a constant pitch. Of this matrix, a pixel measurement section 66 is configured to measure one pixel of a color negative image using 3.times.3 photoelectric conversion sections. This pixel measurement 66 is surrounded by a dotted line.

When reading out the signals of each photoelectric conversion unit, either add up and read out the signals of the same color within the same pixel, or
Alternatively, the color signals may be read out in a mixed form, loaded into the microcomputer 43, and then added within the pixel before being stored in the RAM 45. In this embodiment, since the photoelectric conversion sections of the same color are appropriately scattered within the pixel measurement section 66, the occurrence of color registration can be considerably reduced. Simply, 3 pieces lined up horizontally or vertically, or 3 pieces forming a triangle.
The pixel measuring section may be composed of two photoelectric conversion sections.
It is convenient if the number of pixel measuring units 66 is set to be the same as the number of pixels of the color image displayed on the monitor, since the automatically determined skin color area and the monitor image match. Note that if the number of pixels in the pixel measuring section 66 is small, interpolation processing may be performed so that the number of pixels becomes the same, and then this may be written into the memory. In this case, because the number of pixels is small, color
The boundaries of the skin-colored portion displayed on the CRT50 are jagged.

FIG. 3 shows the functions of the microcomputer. The skin color memory section 70 stores data defining a skin color range. This skin color can be defined, for example, by a hatched ellipse in two-dimensional coordinates centered on the difference between two color densities, as shown in FIG. This fourth
The figure shows skin color in a positive image for convenience. Conveniently, it can be defined as a rectangle with sides parallel to the axis in two-dimensional coordinates.

The data of the skin color memory section 70 and the RAM 45
The three color densities of each pixel stored in are sent to the main image determination section 71, where skin color determination is performed for each pixel. This skin color determination is performed using the three-color density measured on the negative or the density difference between two colors derived therefrom, so that the actual color on the negative corresponds to the color on the positive image (complementary color). In the following description, the invention will be explained using colors on a positive to make it easier to understand. The definition of skin color and the method of detecting skin color pixels are described in, for example, JP-A-52-156624 and JP-A-53-
Details are given in issue 145620.

The determination result of the main image determination unit 71 is sent to the image area determination unit 72, and data indicating whether the image is skin color or not,
For example, a binary signal of "1" is written when the color is skin-colored, and "0" when the color is not skin-colored. This image area determining section 72 is composed of an image area table having an address corresponding to each pixel. Furthermore, in case of a misjudgment, the position of the main image is indicated using the light pen 53. When this manual designation is performed, the automatically detected data is automatically cleared, and the data from the position detector 52 is written into the image area table. Furthermore, if a skin-colored portion does not exist, operating the reset key 57 clears the data in the image area table.

The write/read control unit 73 controls writing and reading of memories 74a to 74c provided for each color and reading of data in the image area table of the image area determining unit 72. This memory 74a to 74c
are negative/positive conversion processing, image processing, and A/D.
Converted color video signal (R, G, B)
is written. This image processing includes γ correction and color correction, which are performed by the image processing circuit 75.
Further, A/D conversion is performed by an A/D converter 76.
During monitoring, the color video signals stored in the memories 74a to 74c are read out, converted into analog signals by the D/A converter 77, and then sent to the amplifier circuit 78. This amplification circuit 78 changes the amplification factor in two stages according to the data read out from the image area determining section 72. The color video signal, in which the skin color portion is greatly amplified compared to the background image, is sent to the color CRT 50 via the driver 79, and the color image 51, in which the skin color portion is high brightness, is converted into a color video signal.
Displayed on CRT50.

When the printing start key 58 is operated, the positional information of the main image and the background image read from the image area determination section 72 is sent to the average color density calculation section 82, and the average color density is calculated. This average color density calculation section 8
2 is composed of a main image average color density calculation section 83 and a background image average color density calculation section 84, which calculates the average density of each color for each image.
That is, the average color density calculation unit 83 reads out the color density of each pixel constituting the main image from the RAM 45, calculates the red average density, green average density, and blue average density, respectively, and similarly calculates the average color density. The unit 84 calculates the average color density of the background image. As this average color density, an arithmetic mean value obtained by adding the color density of each pixel and dividing it by the number of pixels, an intermediate value between the maximum value and the minimum value in the image, etc. are used.

The average color density of each image is sent to the gray density difference calculating section 85 in order to calculate the gray density difference used as scene classification information. Here, for each image,
The red average density, green average density, and blue average density are added and the average value (gray density value) is calculated.
Next, the difference between the two gray average densities is calculated.

The feature calculation unit 86 calculates the feature used in the exposure calculation formula from the color density of each pixel stored in the RAM 45, sends it to the exposure calculation unit 87, and uses the selected exposure calculation formula. By substituting them, the blue exposure amount, green exposure amount, and red exposure amount are respectively calculated. The calculated exposure amount signals for each color are sent to the filter adjustment section 19, and the insertion amounts of the color filters 16 to 18 into the optical path 20 are adjusted respectively.

As the exposure amount calculation formula, for example, JP-A-52-
23936, 54-28131, extreme value information (maximum value, minimum value), screen position average density information (upper half or lower half of the screen), histogram information, etc. as feature quantities. An exposure amount calculation formula is used. Further, the average density of the main image and the average density of the background image may be added to these exposure calculation formulas as feature quantities.

FIG. 5 shows a procedure for exposure control, and the operation of the photographic printing apparatus shown in FIG. 1 will be briefly explained with reference to FIG. Before starting printing, each of the color filters 16 to 18 is retracted from the optical path 20.
A mirror 32 is also inserted into the optical path 20. The white light emitted from the white light source 10 in a dimmed state is sufficiently diffused when passing through the diffusion tube 11, and then illuminates the color negative film 12 from below.
The light transmitted through the color negative film 12 passes through a lens 24 and a mirror 32 before reaching a half mirror 34. The light transmitted through this half mirror 34 is incident on a sensor unit 35, and the reflected light is incident on a color TV camera 36.

The sensor unit 35 scans the color negative image, measures the three color components of each pixel, and generates a color signal for each pixel. This color signal is
After being digitally converted and logarithmically converted, it is written into the RAM 45 of the microcomputer 43 in a separated state for each color. In addition, color TV camera 36
The color video signal output from the controller 49 is sent to the controller 49 after being subjected to negative/positive conversion.
This controller 49 performs image processing and digital conversion on the color video signal, and then writes the signal into memories 74a to 74c provided for each color. Writing and reading from the memories 74a to 74c are controlled by a writing/reading control section 73. The color video signals read from each of the memories 74a to 74c are digitally converted, signal amplified, and then sent to the driver 79. This driver 79 drives the color CRT 50 to display a positive image 51 on its display surface.

After capturing the three-color density signals, the microcomputer 43 automatically detects skin-colored pixels.
That is, with reference to the skin color definition written in the skin color memory unit 70, it is determined from the three color densities of each pixel read from the RAM 45 whether it is a skin color. This determination result is determined by the image area determination unit 72.
"1" is written in the image area table if the image is a skin color, and "0" is written otherwise.

The write/read control section 73 has a memory 74.
a to 74c and the image area table are read out at the same time. The color video signals read from the memories 74a to 74c are digitally converted and then sent to the amplifier circuit 78. This amplifier circuit 78 receives data read from the image area table.
Since it is input as an amplification factor adjustment signal, when data "1" indicating skin color is input, the color video signal of each color is greatly amplified. As a result, in the positive image displayed on the color CRT 50, the automatically determined skin color portion has a higher brightness than the surrounding background image. FIG. 6 shows this state, in which the hatched part of the face is determined to be skin-colored and has a high brightness that can be identified.

The positive image displayed on the color CRT 50 is observed to confirm whether the skin area of the person has been correctly determined and whether this area has high brightness.
If the skin of a person has high brightness,
Automatic detection of the main image has been performed correctly, and at this time the printing start key 58 is pressed as will be described later.
On the other hand, if the part with high brightness is, for example, a wall, the main image may be misidentified.
In this case, the light pen 53 is used to trace the outline of the skin-colored area and the skin-colored area is manually input. The coordinate position of this manually designated skin color portion is detected by the position detecting section 52, and is sent to the image area determining section 72, where the data is rewritten. This new data is read out by the write/read control unit 73 and sent to the amplifier circuit 78, so that the manually designated portion is displayed with high brightness on the color CRT 50. Further, there is a case where a skin-colored portion is not present due to a misidentification of automatic detection, but in this case, the reset key 57 is operated to clear the data in the image area determining section 72.
In this case, the color image displayed on the color CRT 50 has no high brightness portion.

After automatic detection of the main image or manual instruction,
When the printing start key 58 is turned on, the mirror 32 is retracted from the optical path 20 and the white light source 10 emits full light. In addition, the average color density calculation section 82 operates, and refers to the data stored in the image area table to divide the three color densities of each pixel read from the RAM 45 into the main image and the background image. The image feature amount of the main image is calculated from the three color densities of the pixels that make up these main images, and the image feature amount of the background image is extracted from the three color densities that make up the background image. Scene classification is performed from each of the obtained image feature amounts, and an exposure calculation formula prepared in advance for each scene is selected.

The exposure amount for each color is calculated by substituting feature amounts for exposure control into the selected exposure amount calculation formula. Depending on the calculated exposure amount of each color, the color filters 16 to 18 of the complementary color are retracted from the standard position or further inserted toward the center of the optical path 20, and the three-eclipse component of the printing light is adjusted.

Next, the shutter 25 is opened for a certain period of time, and a color negative image is printed onto the color photographic paper 26. After this printing, the color photographic paper 26 and the color negative film 13 are fed by one frame. Along with this, the filter adjustment section 19 adjusts the color filter 16
18 are returned to their standard positions in the optical path 20, and the white light source 10 is also dimmed. When this new frame is set at the printing position, the main image is automatically detected again as described above, and the main image is displayed based on the automatic detection.

In the embodiment described above, the color filters 16 to 18 are used to adjust the exposure amount of each color to create a printed photograph with good density and color balance. but,
Depending on the color negative image, color filters 16 to 18
In some cases, it may not be possible to fully compensate for this, but in this case,
The exposure time of the shutter 25 may be shortened or extended in steps, and the amount of insertion of the color separation filters 16 to 18 into the optical path may be adjusted accordingly. In addition, in the exposure amount calculation formula, the color correction amount is calculated and the color filters 16 to 18 are controlled, and when the exposure amount is inappropriate (over negative image, under negative image, backlit negative image),
The exposure time of the shutter 26 may be extended or shortened from the standard exposure time by calculating the density correction amount separately.

Next, the flowchart shown in FIG. 5 will be explained in detail with reference to FIGS. 7 and 8. In FIG. 7, the color density of each pixel sequentially read out from the RAM 45 is divided into a main image and a background image with reference to the determination results stored in the image area table. Then, within each image area, add the density value for each color,
And check the number. Here, D1 is the density of pixels forming the main image, and D2 is the density of pixels forming the background image. Further, i represents an individual pixel, and j represents a color. j=1 is red, j=2 is green, and j=3 is blue.
N1 is the number of pixels included in the main image area, and N2 is the number of pixels included in the background image area.

Since the density value added for each color in each area is divided by the number, the average color density of the main image area and the average color density of the background image area are calculated. This average color density is marked with a horizontal bar above the symbol. Gray densities DW ₁ and DW ₂ are calculated from the average color densities thus obtained, and the difference between them, ΔD, is used as scene classification information.

FIG. 8 shows an example of scene classification.
Scenes are roughly classified into two types depending on whether a skin-colored portion is present or not. Next, if a skin-colored portion is present, it is subdivided based on the size of ΔD. This subclassification by ΔD is performed in four stages: less than −0.10, −0.10 to less than 0.05, 0.05 to less than 0.20, and 0.20 or more. Based on these classifications, one of the exposure calculation formulas F1 to F5 is selected.

The following is used as the exposure amount calculation formula F1, and the exposure amount is calculated for each color using the feature amount of that color, and the color filters of the corresponding color and complementary color are adjusted respectively. Here, j represents any one of red, green, and blue.

X _j = -3.59 + (3.7 x DFMX _j ) + (1.8 x DFMI _j ) - (3.7 x DCA _j ) + (1.1 x DCMX j ) + (0.5 x DCMI _j ) - (1.0 x DLWA _{j )} + (1.1 xDLWX _j ) - (0.8 x NHCN _j ) - (2.3 x NLCN _j ) + (0.5 x NSD _j ) - (0.6 x NGRAY) The feature amounts used in the exposure calculation formula are as follows.

DFMX _j : Maximum density of the entire screen DFMI _j : Minimum density of the entire screen DCA _j : Average density of the center of the screen DCMX _j : Maximum density of the center of the screen DCMI _j : Minimum density of the center of the screen DLWA _j : Minimum density of the bottom half of the screen Average density DLWX _j : Maximum density in the lower half of the screen NHCN _j : 0.8 x (DFMX _j - DFMI _j ) + Number of pixels with density greater than DFMI _j NLCN _j : 0.2 x (DFMX _j - DFMI _j ) + Density smaller than DFMI _j Number of pixels NSD _j : Average contrast at the periphery of the screen NGRAY: Number or area of gray pixels in the screen Other exposure calculation formulas F2 to F5 are used with coefficients changed depending on the scene. Of course, an exposure amount calculation formula using another feature amount may be used. In addition, the exposure amount calculation formulas F1 to F5 are calculated as the average exposure amount of one color or three colors without calculating each of the three colors, and the exposure amount is calculated using the color balance amount of the three colors calculated by another method. You may decide.

In the above-described embodiment, the main image, which is a skin color, is displayed with high brightness, but the main image portion may be made to blink instead. FIG. 9 shows the main parts of this embodiment, and the same parts as shown in FIG. 3 are given the same reference numerals. A gate 91 is provided between the image area determination section 72 and the amplification circuit 90, and a timer 92 allows the gate to be set at a predetermined period, for example.
Opens and closes at 0.5 second intervals. As shown in FIG. 10, during the period when the gate 91 is closed, the main image and the background image are amplified with the same amplification factor, and during the period when the gate 91 is open, the amplification factor of the main image is the same as that of the background image. It is smaller than that, for example, zero. This causes the main image to blink on the color CRT 50.

Although the above-mentioned embodiment is a photographic printing apparatus, the present invention can also be used in a negative pre-verification apparatus.
In this case, of course, the color filter 16
-18, shutter 25, color photographic paper 26, etc. are no longer necessary. FIG. 11 shows an embodiment in which the present invention is applied to a negative pre-verification device, and only the parts different from FIG. 4 are shown.

The negative pre-verification device detects negatives that cannot be properly printed in an automatic photoprinting device, and inputs a correction amount for the automatically calculated exposure amount based on the operator's experience. Therefore, the amount of correction changes depending on the exposure control method of the automatic photoprinting apparatus used. Therefore, in this embodiment, the exposure amount calculation formula of the automatic photo printing apparatus used is written in the calculation section 95.

The calculation unit 95 calculates the exposure amount for each color using the three-color density of each pixel read from the RAM 45. The obtained exposure amount of each color is sent to the subtraction unit 96, and the difference with the exposure amount of each color calculated using the selected arithmetic expression is calculated. This difference in exposure amount is the correction amount, which is sent to the key stage number conversion section 97, converted to the number of correction key stages, and then output to a storage medium 98 such as paper tape or floppy disk. At the time of photo printing, the certified color negative film and the storage medium 98 storing the amount of correction are set in the automatic photo printing apparatus.

The arithmetic unit 95 can be used to write an arithmetic expression by operating a keyboard or the like, but instead, a plurality of arithmetic units that execute different arithmetic expressions are provided, and the arithmetic units can be selected depending on the automatic photo printing device used. It is also possible to select.

In the embodiment described above, the entire skin-colored area is displayed, but instead, a part of it is displayed as a spot, such as a high-intensity or blinking cross mark, circle, etc.
It is also possible to display it as a square or the like.

Also, if you simulate a printed photo created with a photo printer and display it on a color CRT,
It is possible to prevent the creation of defective printed photographs. In this case, a lookup table memory is provided between the memory and the A/D converter, and the reference table data is shifted according to the photographic printing exposure amount calculated focusing on the skin tone area, and this is transferred to the lookup table memory. The gradation of the video signal can be corrected by referring to this lookup table. Then, if you observe the color CRT and find that the finish is not satisfactory even with automatic skin tone control,
Enter the correction amount by operating the color correction key and density correction key. When this correction amount is input, the system simulates it again and displays the corrected positive image on the color CRT.

When displaying a simulated photo of this print, if the entire skin-tone area is displayed at high brightness, the finish of the skin-tone area, that is, the main image, cannot be confirmed.
Furthermore, there is a risk of giving a misunderstanding that the exposure is extremely overexposed. Therefore, for example, a finish display key is provided to normally display the skin tone area at high brightness.
When the finishing key is operated, it is preferable to stop the high brightness display of the skin tone area and display a positive image simulating a printed photograph on the color CRT.

Furthermore, in the above-mentioned embodiment, scenes are classified using the image feature values obtained from the main image and the background image, and the exposure amount calculation formula is selected according to this scene classification. For example, the density signals of the pixels of the main image may be weighted and then added, and the exposure amount may be calculated according to this added value.Furthermore, it is possible to add weights to the density signals of the pixels of the main image, and calculate the exposure amount according to this added value. The exposure amount may be calculated separately.

〔Effect of the invention〕

As is clear from the above explanation, in the present invention, the skin color of a person, who is often the main image, is defined in advance, the skin color portion is determined by referring to this definition, and the color negative image is displayed on a monitor displaying a color negative image. Since the skin color portion is displayed, the instruction operation for the main image is simplified, and the main image can be verified with high efficiency. Furthermore, since the automatically determined main images are displayed on the monitor, errors in automatic determination can be easily detected.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a photographic printing apparatus embodying the present invention. FIG. 2 is an explanatory diagram showing an example of an image sensor. FIG. 3 is a functional block diagram of the microcomputer shown in FIG. 1. FIG. 4 is a graph showing an example of the definition of skin color. FIG. 5 is a flowchart showing the procedure of exposure control. FIG. 6 shows a positive image displayed on a color CRT. FIG. 7 is a flowchart showing the procedure for calculating image feature amounts. FIG. 8 is a flowchart showing the procedure for scene classification and exposure calculation formula selection. FIG. 9 is a block diagram of essential parts showing an embodiment in which the main image is displayed blinking.
FIG. 10 is an explanatory diagram showing the blinking state of the main image. FIG. 11 is a block diagram showing the main parts of a negative pre-verification device implementing the present invention. 10... White light source, 11... Diffusion tube, 12...
Color negative film, 16...Yellow filter, 17...Magenta filter, 18...Cyan filter, 25...Shutter, 26...Color photographic paper, 32...Mirror, 34...Half mirror,
35...Sensor unit, 36...Color TV
Camera, 50...color CRT, 51a...skin-colored part, 53...light pen.

Claims (1)

[Scope of Claims] 1. A means for measuring the three-color density of each point of a color original image, a storage means for storing data defining a skin color range in a positive image, and a storage means for storing the measured values of the measuring means and the storage means. a determining means for determining whether or not each measurement point is a skin color by comparing data, an image displaying means for displaying the color original image on a monitor, and controlling the image displaying means in accordance with the determination result from the determining means. ,
1. A main image display device comprising: a control means for displaying a skin-colored area on the image display means in a distinguishable manner. 2. The main image display device according to claim 1, wherein the display means is a color CRT. 3. The main image display device according to claim 1, wherein the display means is a color liquid crystal display device. 4. The main image display device according to any one of claims 1 to 3, wherein the control means displays the entire skin-colored area with high brightness. 5. The main image display device according to any one of claims 1 to 3, wherein the control means blinks the entire skin-colored area.