JPS62180350A - Method and device for indicating principal subject to be photographed - Google Patents

Abstract

PURPOSE:To easily indicate the position of a principal subject to be photographed by lighting the principal subject recorded in an original image in a spot shape, measuring light of each picture element of the original image in the presence of said lighting and finding its density value, and detecting picture elements which have density values smaller than the base density of the original image. CONSTITUTION:A half-mirror 36 is arranged slantingly between a lens 28 and a shutter 29 so as to confirm the position of spot light 25 when the principal subject to be photographed is indicated, and light reflected by the half-mirror 36 is incident on a color TV camera 38 after passing through a lens 37. The color TV camera 38 picks up an image of a negative image recorded in a frame 13a and outputs a video signal. The video signal is decided by a negative/ positive inverting circuit 39 and then sent to a monitor 40, so that the color image is displayed on its display screen. In this case, the spot light indicating the principal subject is displayed as a dark spot through negative/positive inversion, so an optical guide 23 is so moved as to align the dark point with the principal subject to be photographed 26.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a device for indicating the position of the main subject of an original image, which is used in a photographic printing device, a preliminary negative verification device for printing, etc. It is.

[Conventional technology]

In general, original images such as color negative film and color positive film have frames with an underexposed negative image in addition to frames with an appropriate exposure amount for the negative image.

This includes overexposed negative image frames, negative image frames with high contrast, etc. Even if such an improperly exposed negative image is printed, the LATD values (Large Area The LATD value of each color is used to control the blue exposure amount, green exposure amount, and red exposure amount.

In the case where the exposure amount is controlled by the LATD value mentioned above,
This ensures that the entire screen has good density and color balance, but depending on the scene, it may not be possible to accurately reproduce the main subject. In general, if the density and color balance of the main subject are good, the print photograph is often considered to have a good finish, so it is desirable to correct the exposure amount using the density value of the main subject.

Since it is difficult to automatically detect the main subject recorded in the original image, it is necessary to manually specify the main subject. The main object indicating device is a mirror placed above the color negative film, and a color TV camera captures the image of the color negative film through this mirror and displays it on a monitor.The monitor is equipped with a transparent touch panel. There is a known method in which the main subject is indicated by standing up, observing a negative image displayed on a monitor, and touching a part of the touch panel above the main subject with a finger. Furthermore, there are also known devices in which a mouse or a light pen is used instead of a touch panel to indicate the main subject.

(Problems to be Solved by the Invention) In the conventional main subject pointing device described above, since the color TV camera captures a negative image through a mirror, the negative image displayed on the monitor has almost no graphic distortion. No. However,
Since the sensor unit for measuring the three-color density of each pixel of the negative image is arranged diagonally above the negative image, the rectangular negative image becomes trapezoidal due to graphical distortion. For this reason, the pixels of the negative image on the monitor and the negative image formed on the sensor unit no longer correspond, so there is a problem that the main subject cannot be correctly indicated.

[Means for solving problems]

In order to solve the above problems, the present invention uniformly illuminates the entire original image, illuminates the main subject recorded in the original image in spots, and under this illumination condition, each pixel of the original image This method has been improved so that it measures the light using an image sensor to determine its density value, detects pixels whose density values are smaller than the base density of the original image, and determines these to be pixels of the main subject. .

The spot illumination can be performed by placing a small light source under the original image, or by placing a light guide transmitting light from the light source under the original image and moving it in two dimensions. As the image sensor, an area sensor or a line sensor is used. When using a line sensor, it is necessary to move either the line sensor or the original image during photometry.

The position information of the main subject is sent to an exposure control system and is used, for example, to weight the density of the main subject. Also, based on the position information of the main subject, the original image is divided into the main subject and the background, and each area is divided into density r11. You can calculate the exposure by extracting the amount and substituting these into the exposure calculation formula, or classify the original image into scenes based on the color of the main subject and the difference in density between the two areas, and create a preset for each scene. A prepared exposure amount calculation formula is selected, and the exposure amount is calculated from the selected exposure amount calculation formula.

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

〔Example〕

FIG. 1 shows an example of a photo printing apparatus for carrying out the present invention. White light emitted from a white light source 10 is diffused within a diffusion tube 11, passes through a negative carrier 12, reaches an original image, for example, a color negative film 13 set in a printing position, and illuminates it from behind. 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 open ends of the rectangular tube 14. Between the diffusion tube 11 and the white light source 10, there are provided a yellow filter 16 for adjusting the blue exposure amount, a magenta filter 17 for adjusting the green exposure amount, and a cyan filter for adjusting the red exposure amount. 18 is arranged, and is partially inserted into the optical path 20 by the filter driving section 19. These filters 16 to 18 are connected to the optical path 20
When the amount of light inserted into the filter is increased, the amount of light of the complementary color of the filter color decreases. The color negative film 13 located on the negative carrier 12 is printed by a solenoid (
It is pressed down from above by a mask 21 driven by a motor (not shown).

A spot illumination section 24 consisting of a light source 22 and a transparent light guide 23 is movably arranged below the negative carrier 12. When specifying the main subject, the spot illumination section 24 is moved directly below the color negative film 13, and the light emitting section 23 of the light guide 23 is moved as shown in FIG.
The spot light 25 emitted from point c is aligned with the main subject 26 of the frame 13a, which is centered at the printing position. In this embodiment, since the main subject 26 is a person, the spotlight 25 is focused on the person's face. Note that in order to make the spot light 25 easier to see, colored light, for example, red light, may be used as the spot light.

A lens 28 is arranged above the color negative film 13, and a negative image is formed on the color photographic paper 30 while the shutter 29 is open. This shutter 29
The opening and closing of the shutter drive section 31 is controlled by a shutter drive section 31. Further, when printing of one frame of the color photographic paper 30 is completed, the color photographic paper 30 is wound around the take-up reel 32 for one frame, and the unexposed portion is pulled out from the supply reel 33.

In order to confirm the position of the spot light 25 when indicating the main subject, a half mirror 36 is arranged at an angle between the lens 28 and the shutter 29, and the light reflected by this half mirror 36 is reflected by the lens. After passing through 37, the light enters a color TV camera 38. This color TV camera 38
captures the negative image recorded on the frame 13a and outputs a video signal. This video signal is transferred to the negative/positive inverting circuit 3
After the judgment is made in step 9, the image is sent to the monitor 40, and a color image is displayed on the display surface thereof. In this case, since the spotlight for indicating the main subject is displayed as a dark spot due to negative/positive inversion, the light guide 23 is moved so that this dark spot coincides with the main subject 26. In order to prevent a decrease in the light intensity, a pivotable mirror may be provided in place of the half mirror 36, and the photo printing may sometimes be retracted from the optical path 20. Furthermore, the color TV camera 38 and monitor 40 may be omitted. Alternatively, a transmissive screen may be placed on the imaging plane of the lens 37.

A sensor unit 1-42 for measuring each pixel of the negative image is installed diagonally above the printing position.

This sensor unit 42 is composed of an M image lens 43 and an image area sensor 45 such as a CCD type or MOS type with a BGR mosaic filter or BGR stripe filter 44 attached to the front surface, and reads each pixel of the negative image. outputs a time-series signal that is a mix of blue, green, and red signals. This time series signal is.

The signal is converted into a digital signal by the A/D converter 46, and then sent to the logarithmic converter 47, where it is subjected to logarithmic conversion. The obtained blue density, green density, and red density signals are taken into the microcomputer 49 via the I10 boat 48, separated for each color, and written into the RAM 50. As is well known, this microcomputer 49 has an I10 board 48° CPU51. RAM50. It is composed of a ROM 52, and calculates the exposure correction amount and controls each part, which will be described later. The calculated exposure correction amount for each color is sent to the filter driving section 19, and the amount of insertion of the filters 16 to 18 is adjusted.

The keyboard 54 has input keys for color correction and density correction.
55, a switch 56 for lighting the light source 22,
A measurement start key 57 for reading the designated position of the main subject, a print start key 58 for starting printing, and a base density measurement key 59 for measuring the base density are provided.

FIG. 2 shows a state in which the main subject is indicated. The light guide 23 is formed into a prismatic shape made of transparent acrylic or transparent glass, and has a light incident part 23 at one end thereof.
The light from the light source 22 enters the light guide 23 from a. Further, the lower surface of the tip of the light guide 23 is cut at 45 degrees, and the light that has passed through the inside of the light guide 23 is reflected upward on the slope 23b and exits from the light emitting portion 23c. This light guide 2
3 is movably provided at a position close to the lower surface of the color negative film 13, so that the light emitted from the light emitting part 23c can illuminate a part of the frame 12a in a spot shape. This spot light illuminates strongly so that the density of the illuminated area is lower than the base density when illuminated with a white light source. Therefore, it is preferable that the white light source 10 is dimmed during measurement, and that the white light source 10 is made to emit full light during printing. As the light source 22, for example, an LED is used.

Next, the operation of the above embodiment will be explained with reference to FIG. 3, which shows the functions of the microcomputer.

When the power is turned on, the white light source 10 emits light, and the white light emitted from it is sufficiently diffused when passing through the diffusion tube 11, and then passes through the opening of the negative carrier 12 to illuminate the color negative film 13 from below. . The light transmitted through the color negative film 13 is transmitted through the lens 28. half mirror 3
6. The light passes through the lens 37 and enters the color TV camera 38. The color TV camera 38 takes a negative image of the frame 13a at the printing position and generates a video signal.

This video signal is inverted into a positive image by a negative/positive inversion circuit 39, and then sent to a monitor 40 for color display.

Before starting negative verification, the base density of the color negative film 13 is measured by operating the base density measurement key 59. When this base density measurement key 59 is operated, the negative image illuminated with white light is photometered by the sensor unit 42. That is, since a negative image is formed on the image area sensor 45 by the imaging lens 43, when the first measurement is started, the image area sensor 45 generates a time series signal obtained by photoelectrically converting each pixel of the negative image. Output.

Since this time-series signal uses the BGR stripe filter 44, it has a mixed form of a blue signal, a green signal, and a red signal.

The time-series signal output from the image area sensor 45 is sequentially subjected to digital conversion and logarithmic conversion, and is then taken into the microcomputer 49 as a density signal. The microcomputer 49 separates the density signals for each color and then writes them into the memories 63 to 65, respectively.

After writing into the memories 63 to 65, the microcomputer 49 reads out the three-color density signals of each pixel, sends them to the calculation section 66, and calculates the arithmetic mean. A white density value is calculated by this calculated average, and the obtained white density value is sent to the base density setting section 68 via the switch 67. This base density setting section 68 detects the minimum value of the white luminance value and stores this in the memory as the base density. The switch 67 is ON only when measuring base concentration! , and
It is turned OFF when specifying the main subject.

After measuring the base density as described above, a negative test is performed for each frame. During this negative verification, frame 1 displayed on the monitor 40
Observe the color image of 3a. Based on the characteristics of this color image, if it is predicted that the main subject will not be properly finished with automatic exposure using the LATD method, the switch key 56 is turned on, and the ArD method is used to print enough photographs. If it is determined that the main subject can be determined, or if the main subject cannot be determined, the switch key 56 is turned OFF.

When the switch key 56 is turned on, the light source 22 emits light and enters the light into the light incidence part 23a of the light guide 23. The light incident on the light guide 23 is reflected inside and reaches the inclined surface 23b, where it is reflected upward to the light exit section 23.
c, and brightly illuminates a part of the frame 13a in a spot-like manner. This spot-shaped illuminated area is visible on the monitor 4.
0 is displayed as a dark spot, so the light guide 23 is manually moved in a two-dimensional direction so that this dark spot overlaps the main subject 26.

When the photometry start key 57 is pressed after specifying the main subject, the negative image is photometered by the sensor unit 42 with the entire negative image illuminated by the white light source 10 and only the main subject 26 illuminated by the spotlight 25. and the obtained three-color density values are written into memories 63-65. This memory 6
The three color density values stored in pixels 3 to 65 are sent to a calculation unit 66, where the white density value of each pixel is calculated. This white density value is sent to the pixel detection section 69, where it is compared with the base density value set in the base density setting section 68.

Pixels of the main subject that are brightly illuminated by the spotlight 25 have a value smaller than the base density value, so the pixel with this value is detected, this pixel is determined to be the pixel of the main subject, and this is extracted as the position information of the main subject and stored in the memory 70.

After inputting the positional information of the main subject, when the printing start key 58 is operated, only the light source 22 is forcibly turned off, so that the frame 13a is illuminated only by the white light source 10. In this state, the sensor unit 42 measures the negative image, and the obtained three-color density values of each pixel are stored in the memories 72 to 74, respectively.

The density of each pixel written in each of these memories 72 to 74 is sent to units 75 to 77, respectively, with weights provided for each color. These weighted parts 75 to 77 are
Since the weighting coefficient from 8 and the main subject position information from the memory 70 are input, the weighting coefficient is multiplied by the density of a plurality of pixels corresponding to the position of the main subject. For this weighting coefficient, a value larger than "1" is generally used, but if this value is extremely large, it will cause a spot.

This is photometry, and exposure is controlled based on the density of the main subject.

After weighting the density of the main subject in units 75 to 77, the weighting is sent to LATD value (Large Area Average Transmission Density) calculation units 79 to 81 provided for each color, where the density of each pixel is calculated. An average is calculated. The arithmetic mean obtained is
The LATD value is sent to the exposure correction amount calculation unit 82, and the exposure correction amounts for blue, green, and red are calculated. This calculated exposure correction amount for each color is sent to the filter drive unit 19,
The amount of insertion of the filters 16 to 18 into the optical path 20 is adjusted.

After the filters 16 to 18 are activated, the microcomputer 49 activates the shutter drive section 31 to open the shutter 29 and start printing.

When a certain period of time has elapsed since the start of this printing, the shutter 29 is closed to end the printing. After that, the filter driver 19 moves each filter 16 to 18 along the optical path 20.
evacuate from. Along with this, the take-up reel 32
The exposed color photographic paper 30 is wound up for one frame, and the unexposed color photographic paper is pulled out from the supply reel 33 and set at the exposure position. Further, after the mask 21 is slightly raised, the color negative film 13 is transferred by one frame, a new frame is set on the negative carrier 12, and the mask 21 is pressed from above again. Along with this, LED
29 starts emitting light again, and preparations are made to specify the main subject for this new frame.

Since the light guide 23 is transparent, the color photographic paper 3
Although there is no risk of being burned into zero, in order to ensure reliability, it is better to evacuate the light guide 23 from the optical path 20. However, if the light guide 23 is placed apart from the color negative film 13, the light guide 23 can be moved one by one to the optical path 20.
There is no need to evacuate the area. FIG. 4 shows this embodiment, and the same members as in FIG. 2 are given the same reference numerals.

In this embodiment, a transparent holder 85 is fixed on the light emitting part 23c, and a condensing lens 86 is housed in the transparent holder 85. This condensing lens 86 illuminates the color negative film 13 with the light emitted from the emission section 23c in a spot shape. Note that an imaging lens may be used instead of the condensing lens.

In the embodiment described above, the base density is measured before negative verification, but since this base density is almost determined depending on the type of color negative film, the base density may be input from the keyboard 54.

Further, the base density may be determined from the density measurement performed when the printing start key 58 is operated.

Furthermore, when specifying the main subject, by adjusting the brightness of the white light source so that the base density is zero, pixels with negative density values can be detected and determined to be pixels of the main subject. I can do it.

Further, in the above embodiment, a spot light source is used in addition to the white light source, but instead of the spot light source, a partially transparent ND filter may be used. The ND filter is moved under or over the color negative film to match the transparent portion to the main subject.

Although each of the embodiments described above is a photographic printing apparatus, the present invention may also be applied to a negative inspection apparatus. In this case, a monitor can be omitted since the test position can be looked into. Then, the information indicating the position of the main subject specified at the time of negative verification is output to a tape or floppy disk, and this is loaded into the photo printing apparatus. Furthermore, the present invention provides C
A display device or photo printing using RT can be used in the device, and in this case, the image is processed so that the designated main subject has a specific color and brightness, and this is displayed on the CRT. In addition, by specifying a part of the main subject, the computer automatically extracts the part with the same color or a color close to this part, and determines this extracted part to be the main subject. It's okay.

〔Effect of the invention〕

As is clear from the above explanation, since the present invention directly indicates the main subject on the original image, compared to the method of indirectly indicating the main subject on the original image displayed on the monitor, No positional deviation occurs in the image sensor, and the position of the main subject can be easily indicated.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a photo printing apparatus for carrying out the present invention. FIG. 2 is a detailed explanatory diagram of the present invention showing a state in which spot light is irradiated. FIG. 3 is a functional block diagram of the microcomputer shown in FIG. 1. FIG. 4 is a sectional view of essential parts showing another embodiment of the present invention. 10... White light source 11... Diffusion tube 13... Color negative film 13a... Frame 22... Light source 23... Light guide 24... Spot illumination section 25... Spot light 26... Main subject 29... Shutter 30... - Color photographic paper 35 - Half mirror 40 - Monitor 42 - Sensor unit 45 - Image area sensor 54 - Keyboard 56 - Switch key 57 - Measurement start key 58 - Start printing key 59 - Base Concentration measurement key 86: Condensing lens. Procedural amendment March 5, 1986

Claims (6)

[Claims] (1) The entire original painting is illuminated uniformly, and the main subject recorded in the original painting is illuminated in spots, and each pixel of the original painting is photometered with an image sensor under this illumination condition, and its density value is measured. A method for specifying a main subject, comprising: determining a pixel whose density value is smaller than the base density of the original image, and determining that the pixel is a pixel of the main subject. (2) A main subject indicating device for indicating a main subject recorded in an original picture, comprising: a full-surface illumination means for illuminating the entire original picture; and a main subject arranged below the original picture so as to be movable in two dimensions a spot illumination means for illuminating the original image in a spot-like manner; a means for observing the original image; a density measuring means for measuring the density of each pixel of the original image illuminated by the entire surface illuminating means and the spot illuminating means; and the density measuring means. means for comparing the density value of each pixel measured by the means with a base density value of the original image, and detecting a pixel having a density value smaller than the base density value; 1. A main subject indicating device comprising means for storing positional information of the subject as pixels of the subject. (3) The spot illumination means has a light entrance part and a light exit part, and is arranged opposite to a light guide movable in two-dimensional directions below the original image and the light entrance part of this light guide. 3. The main subject pointing device according to claim 2, further comprising a light source. (4) The light guide has a transparent prismatic shape, and the lower surface of the tip thereof is cut diagonally, and the upper surface located on the slope is used as a light emitting part. The main subject pointing device according to item 3. (5) A light guide is disposed at a predetermined distance from the original image, and a condensing lens or an imaging lens is attached above the light exit portion of the light guide. Main subject pointing device as described. (6) The main subject pointing device according to claim 3 or 5, wherein the light source is an LED.