JP2888558B2 - Photo printing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic printing method, and more particularly to a photographic printing method for determining a printing exposure amount using the position and luminance of a subject recorded at the time of shooting. is there.

[Conventional technology]

With current photographic prints, the photographing situation and the intention of the photographer are estimated from the image recorded on the photographic film, so that the photographer may be dissatisfied with the photograph. Therefore, there is known a camera that records various kinds of information on a photographic film at the time of taking a photograph in order to create a print photograph that meets the photographer's intention. For example,
JP-A-51-117632, JP-A-52-1333, and JP-A-52-30
Japanese Patent Publication No. 429 describes that the type of photographing illumination light is recorded on a photographic film.
Japanese Patent Publication No. 21432 describes that trimming information is recorded. Also, Japanese Patent Application Laid-Open Nos. 50-30517 and 55
JP-A-10-19332 and JP-A-54-2115 describe recording the type of a main subject.

As an exposure control method of a camera, a method of detecting a main subject by using a distance measuring device and controlling the exposure based on the luminance of the main subject is known. For example, JP-A-59-31
No. 933 discloses that a subject is measured in a plurality of distance measurement areas, and among a plurality of obtained subject distances, the closest one is set as a main subject, and the rest is set as a background subject. An exposure control method is described in which the brightness of the subject is compared with each other, the scene is classified according to the degree of the difference, and an exposure program prepared for each classification of each shooting scene is selected. Japanese Patent Laying-Open No. 62-58228 describes a method of dividing a shooting scene into two distance measurement areas, measuring the luminance of these distance measurement areas, and selecting the smaller one of them to control the exposure. . Furthermore, JP-A-62-255921 discloses that
If only one ranging area has detected the subject, spot metering is performed. If there are multiple subjects and the subject exists in the center ranging area, center-weighted metering is performed. Describes a method of controlling exposure by average photometry in a predetermined area when no object is detected.

[Problems to be solved by the invention]

In a photographic printer, the brightness of the main subject cannot be known, so that it is impossible to use the above-described camera exposure control method. Further, since the ranging area has a certain size, the subject detected by the ranging device is not necessarily the main subject itself, but may be, for example, a part thereof or a background subject. Therefore, if only the part on the screen corresponding to the distance measurement area is determined to be the main part and the printing exposure amount is determined using the characteristic value obtained from this, calculate the appropriate printing exposure amount. Can not be done.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photographic printing method capable of reproducing a main portion density with high accuracy.

[Means for solving the problem]

In order to achieve the above object, the photographic printing method of the present invention records a measured luminance of a main subject and a position of the main subject on a photographing screen on a recording medium at the time of photographing, and reads the measured luminance from the recording medium at the time of photograph printing. The position and the luminance of the main subject are read, and a range defined on the photographing screen with the read position of the main subject as the main part is used as a main part. The printing exposure amount is determined using the weighted feature values.

[Action]

At the time of photographing, the position of the main subject detected by the distance measuring device and the luminance of the main subject measured by a distance measuring sensor or a dedicated sensor are recorded on a recording medium. At the time of photo printing, the main part is determined based on the position of the main subject read from the recording medium. The main part is measured by a scanner to extract characteristic values such as maximum density and minimum density.
On the other hand, the characteristic value of the main part is weighted according to the luminance of the main subject read from the recording medium, and the printing exposure amount is calculated using the weighted characteristic value.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a camera for recording information on the position and luminance of a main subject. In this figure, the photographing scene 10 is schematically shown as a plane, and distance measuring areas T1 to T9 are drawn on the photographing scene 10. The light projecting unit 11 projects the spot-shaped infrared light emitted from the light source 12 toward the photographing scene 10, and sequentially scans the distance measurement areas T1 to T9. Each ranging area
While sequentially scanning T1 to T9, the infrared light reflected by the subject 13 passes through the lens 14 and enters the incident position detecting means, for example, the image sensor 15. The presence or absence of the subject is detected based on whether or not the reflected light from the subject 13 has entered the image sensor 15, and the distance to the subject 13 is measured from the incident position of the reflected light.

An X-axis 18 is attached to the light source 12.
The shaft 18 is rotatably held by a holder 19. A Y-axis 20 is fixed to the holder 19. Further, the X-axis 18 is connected to an X-direction scanning unit 21.
The light source 12 is vertically swung by a pulse motor (not shown). A Y-direction scanning section 22 is connected to the Y-axis 20, whereby the light source 12 swings in the horizontal direction. controller
25 controls the X-direction scanning unit 21 and the Y-direction scanning unit 22 to cause the light source 12 to scan two-dimensionally. The controller 25 includes a pulse counter, detects the scanning position of the light source 12 with respect to the shooting scene by counting the driving pulses sent to each of the scanning units 21 and 22, and scans the distance measurement areas T1 to T9. The light source 12 is caused to emit light only when. The position signal of each of the distance measurement areas T1 to T9 where the light source 12 emits light is sent to the distance detection unit 26.

The distance detection unit 26 obtains the position where the reflected light is incident from the time-series signal of the image sensor 15, and, based on the incident position and the position signal of the distance measurement area, the position of each subject existing in each of the distance measurement areas T1 to T9. Detect distance. In the embodiment shown in FIG. 1, since the subject 13 exists at a distance that can be measured (usually 4 to 5 m), the subject distance obtained in the distance measurement area T4 is used as the shooting distance (focusing distance). Also, this distance detector
26 selects one subject distance according to a predetermined program when subjects at different distances are present in a plurality of distance measurement areas T1 to T9. For example,
In the case of short-range priority, the shortest one of a plurality of detected object distances is selected, and this is set to a photographing lens setting mechanism.
Send to 27.

The position of the main subject on the screen can be known by checking in which ranging area the main subject is detected. Therefore, in this embodiment, position information indicating the center position of the distance measurement area T4 is sent to the barcode data generation circuit. Further, the distance measuring unit 26 sends to the luminance measuring unit 29 the positional information of the pixel of the image sensor 15 on which the reflected light from the main subject has entered. After the light emitting unit 11 finishes projecting light, the luminance measuring unit 29 extracts the signal of the pixel specified by the position information from the time-series signal output from the image sensor 15, and extracts the signal of the pixel of the main subject. The information is sent to the barcode data generation circuit 28 as information.

The photographic lens setting mechanism 27 sets the photographic lens 30 at a position corresponding to the photographic distance when a release button (not shown) is completely pressed. The shutter drive unit 31 is activated by the setting completion signal of the photographing lens 30, and the shutter
Opening and closing 32 exposes photographic film 33. Further, in synchronization with the operation of the shutter drive unit 31, the barcode data generation circuit 28 is operated to convert the position information and the luminance information of the main subject into barcode data. This barcode data is sent to the barcode recording device 35 via the driver 34.

The bar code recording device 35 includes a liquid crystal panel that generates a bar code, and a light source that illuminates the liquid crystal panel. The bar code is burned in close contact from behind the photographic film 33. In this embodiment, the photo film is used.
Record the barcode while the 33 is stopped,
The barcode may be recorded in synchronism with the frame advance. In this case, since the barcode recording device needs to record only one barcode, its structure is simplified. Also, marks, characters, and the like may be recorded instead of the barcode.

FIG. 2 shows an example of a developed photographic film, and distance measuring areas T1 to T9 are indicated by dotted lines for convenience of explanation. The main subject 13 is displayed on the screen 33a of the photo film 33.
The image 13a of FIG. And outside the screen 33a,
Position information 37 of the main subject and its luminance information 38 are recorded.

FIG. 3 shows a photographic printer. The white light emitted from the light source 43 is sufficiently diffused in the mixing box 44 so that illuminance unevenness does not occur. The mixing box 44 has a structure in which diffusion plates are attached to both ends of a rectangular tube whose inner surface is a mirror surface.

The film carrier 47 is arranged at the printing position, and the developed photographic film 33 is set therein, and is illuminated with light transmitted through the mixing box 44. In order to ensure the flatness of the photo film 33, a film mask 48 is provided above the print position. This film mask
As is well known, an opening 48 corresponding to the size of a frame is formed, and is lifted up by a solenoid (not shown) when the photographic film 33 is transported, so that the photographic film 33 is pressed during printing.

A bar code reader 50 is arranged in front of the print position, and when the photo film 33 is sent to the print position, the position information 37 and the luminance information 38 recorded in each frame are provided.
And sends them to the calculation unit 51.

Further, a scanner 54 composed of a lens 52 and an image area sensor 53 is disposed diagonally above the print position, and measures the transmitted light of each point of the frame set at the print position. This scanner 54 is, for example, 14
It has × 10 measurement points, and the signal at each measurement point is sent to the signal processing circuit 55, where it is logarithmically converted and digitally converted. A signal corresponding to the density (hereinafter, referred to as a density signal) is sent to the calculation unit 51 by this logarithmic conversion. The calculation unit 51 calculates the printing exposure amount using the characteristic value of the main part, as described later.

Above the print position, a printing lens 58 is disposed, and a photographic paper 60 disposed behind a paper mask 59 is provided.
Then, the image of the set frame is enlarged and projected. A shutter 62 whose opening and closing is controlled by a shutter driving unit 61 is disposed between the printing lens 58 and the printing paper 60.

FIG. 4 shows a main part on the screen determined based on the position information. In the case shown in FIG. 2, the center position P of the distance measurement area T4 is recorded as the position information 37. Therefore, a rectangle of a predetermined size centered on the position P is set as the main portion 65.

Next, an example of calculation of the printing exposure amount performed by the arithmetic unit 51 will be described. First, the operation unit 51 obtains the main part from the position information 37.
65, and then compare the densities DS _j (j represents each point) of each pixel in the main part 65 to obtain a maximum density DS _max and a minimum density D
Extract S _min . The photographing scenes are classified by substituting these two types of densities into the following conditional expressions.

1. DS _max −DS _min ≦ K (for example, 0.2) In the case of a shooting scene that satisfies this condition, the average density D _mean is calculated from the density DS _{j of} each pixel, and this is calculated as the main part density DS.
And the exposure exposure E is calculated by substituting into the following equation.

l _og E = α (DS−DN) + β (1) where the symbols are as follows.

DN: Average density of normal control negative α: Slope coefficient β: Exposure required to properly finish normal control negative 2. DS _max −DS _min > K In this case, density at position P Scene classifications (a) to (c) are performed based on the relationship between the DP and the maximum density DS _max or the minimum density DS _min . Then, the main portion density DS is calculated by using an arithmetic expression prepared for each shooting scene, and the printing exposure amount E is calculated by substituting into the equation (1) as described above.

(A) In the case of DP ≒ DS _{max In} this case, using the subject brightness B _S EV obtained by decoding the brightness information 38 (when the film sensitivity is set to ISO 100), the shooting scene is subdivided into i to iii. I do.

iB _S > K _H (for example, K _H = 10 EV) In such a shooting scene, the main subject often wears white clothes or partially includes a bright sky. For this shooting scene, the maximum density DS _max is calculated using the following equation (2).
And the minimum density DS _min are weighted to calculate the main part density DS.

_{DS = 0.3DS max + 0.7DS min ···} (2) here, "0.3", "0.7" is a weighting coefficient.

ii. As K _L ≦ B _S ≦ K _H K _L , for example, 5EV is used. For such a photographic scene, the main part density DS is obtained by the following equation (3).

DS = 0.5DS _max + 0.5DS _min (3) iii.B _S <K _{L If} this condition is satisfied, the light is diffused.
Even if the main subject is white, the effect is small. For this photographic scene, the main part density DS is calculated using the following equation (4).

For _{DS = 0.7DS max + 0.3DS min ···} (4) (b) DP ≒ DS min In this case, the subject luminance B _S, is subdivided into the following three types of scene IV to VI.

iv.B _S > K _H There are many backlight scenes in which the main part is small, and the main part density DS is calculated from the following equation (5).

DS = 0.2DS _max + 0.8DS _min (5) vK _L ≦ B _S ≦ K _{H Since the} photometry is performed on the black clothes or the shaded area, it is better to correct the brighter one. Therefore, the main part concentration DS is calculated using the following equation (6).

For _{DS = 0.6DS max + 0.4DS min ···} (6) vi.B S <K L dark back other than the main part is also photometry, there is a need for this correction. Therefore, the following formula (7) gives
Calculate DS.

DS = 0.8 DS _max +0.2 DS _min (7) (c) Others In cases other than (a) and (b), the concentration DP is close to the intermediate concentration of the main part 65, and for this, _{vii to Subdivided} into _viii .

vii.B _S > K _{H Since the} light is bright, it is necessary to correct to the maximum density D _max , and the following equation (8) is used for this.

DS = 0.6 DS _max +0.4 DS _min (8) viii.B _S ≦ K _H For such a shooting scene, the following equation (9) is used.

DS = 0.5 DS _max +0.5 DS _min (9) The arithmetic processing of the present invention is not limited to the above-described scene classification and arithmetic expressions (2) to (9). The feature values extracted from the main part are not limited to DS _max and DS _min , but may include a highlight part density, a shadow part density, an average density of a density area similar to the background part, and the like. In short, the range defined with the position of the main subject as the main part is used as the main part, and the characteristic value extracted from this main part is weighted using luminance information or selected (when the weighting coefficient is zero). ). In this way, the main subject density is more accurately obtained, and the printing exposure amount is determined accurately.

Next, the operation of the above embodiment will be described with reference to FIG. At the time of photographing, the composition is determined by adjusting the direction of the camera, and then a distance measurement is started by touching a release button (not shown) with a finger, as is well known. In this distance measurement, the controller 25 operates the Y-direction scanning unit 22 to rotate the holder 19 via the Y-axis 20. The holder 19 rotates the light source 12 in the Y direction (horizontal direction),
The light source 12 emits light during this rotation. This allows the light source
The spot-like infrared light emitted from 12 first scans the distance measurement area T6, and then scans the distance measurement area T7. After the scanning of the distance measurement area T7, the light source 12 rotates together with the holder 19 in the reverse direction and returns to the initial position in the Y direction.

When the light source 12 returns to the initial position, the controller 25
The direction scanning unit 21 is operated to rotate the X-axis 18 clockwise by a certain angle. Immediately after this, the controller 25 activates the Y-direction scanning section 22, and in the middle thereof, makes the light source 12 emit light and scans the distance measuring area T2.
3, T1, T4, T5, T8, T9 are sequentially scanned.

For example, when the main subject 13 exists on the distance measurement area T4, the infrared light reflected by the subject 13 enters the image sensor 15 via the lens 14. This image sensor
The time-series signal read from 15 is sent to the distance detection unit 26, where the incident position is detected. In addition, the distance detection unit 26 has a light source
Since the twelve position signals have also been input, the ranging area currently being measured is identified. Then, the distance of the main subject is detected from the distance measurement area and the incident position of the reflected light. The information on the subject distance is sent to the photographing lens setting mechanism 27, and the position information indicating the position of the distance measurement area T4 on the screen is sent to the barcode data generation circuit.

After the light projecting unit 11 completes the light projecting scan, the distance detecting unit 26 outputs a signal indicating the incident position of the reflected light, and sends the signal to the luminance detecting unit 29. The luminance detecting unit 29 extracts a signal of a pixel of the image sensor on which the reflected light is incident, based on the incident position signal, from the time series signal of the image sensor 15 that is periodically operated, and extracts the signal from the pixel. The luminance information of the subject is sent to the barcode data generation circuit 28. Note that a dedicated sensor for measuring the luminance of the main subject may be used.

When the release button is completely pressed down, the taking lens setting mechanism 27 sets the taking lens 30 at a position corresponding to the taking distance. After this lens setting, the shutter drive unit 31 operates, so that the shutter 32 opens and closes at a predetermined speed, and the photographed scene 10 is transferred to the photographic film 33. Immediately after the operation of the shutter, barcode data representing the position and luminance of the main subject is output from the barcode data generation circuit 28 and sent to the barcode recording device 35 via the driver 34. This bar code recording device 35 is used to store position information represented by a bar code.
37 and luminance information 38 are recorded on the photographic film 33.

When the photographing of one photo film 33 is completed, the photo film 33 is taken out of the camera and submitted to a photo processing laboratory. In the photo processing laboratory, the photo film 33 is developed, and each frame recorded as a latent image and the position information 37 and the luminance information 38 recorded near each frame are converted into a visible image.

The developed photographic film 33 is loaded on a film carrier 47 of a photographic printer shown in FIG. When the frame recorded on the photo film 33 is transported toward the print position, the barcode reader 50 reads the position information 37 and the luminance information 38 and sends them to the arithmetic unit 51.

When the screen 33a is set at the print position, the scanner 54 scans the screen 33a and measures the transmitted light at each point. The photometric value is converted into a density by the signal processing circuit 55 and then sent to the calculation unit 51. The calculation unit 51 calculates the position information 37
Is determined based on the density of each measurement point included in the main part 65, the maximum density DS _max , the minimum density DS _min
Is extracted. By using these density differences, two
They are roughly classified into types, and are further subdivided using the density DP and the luminance B _{S of the} main subject. The main portion density DS is obtained by using an arithmetic expression prepared for each classification, and the printing exposure amount E is calculated from this. The printing exposure amount E is sent to the controller 56.

After calculating the printing exposure amount E, the controller 56 opens the shutter 62 for a time corresponding to the printing exposure amount E via the shutter driving unit 61 and prints the screen 33a on the photographic paper 60 by printing.
Hereinafter, similarly, each screen of the photographic film 33 is sequentially printed and exposed on the photographic paper 60.

In practicing the present invention, distance information of a main subject is recorded on a photographic film, and the main portion 65 is recorded in accordance with the subject distance.
It is desirable to change the size of. Further, the average brightness of the shooting scene or the average brightness of the shooting scene excluding the main subject may be recorded. This makes it possible to accurately determine whether the main subject is white, black, or is affected by the background by comparing the luminance with the brightness of the main subject. Alternatively, information on the camera attitude may be recorded, and the vertical and horizontal lengths of the main part 65 may be changed according to the camera attitude. Furthermore, the color and the distance of the main subject may be recorded, the scenes may be classified using these, and the weighting coefficient may be changed according to the classified photographed scene.

Although the example in which the scene classification is performed using the characteristic value of the main part has been described, the scene classification may be performed using the characteristic value of the part other than the main part, that is, the background part. If there are a plurality of main parts, first calculate the exposure amount for each of them, then calculate the average value of these, and use this as the printing exposure amount. And the present invention may be applied.

Although the above embodiment is directed to density correction, the present invention can be applied to color correction. In this case, a cyan filter, a magenta filter, and a yellow filter are arranged between the light source 43 and the mixing box 44, and the setting positions of the color filters are adjusted in accordance with the exposure amounts of the three colors.

Also, instead of recording distance information on the photo film,
The information may be recorded on a magnetic recording portion formed on the outer periphery of an IC card or a cartridge, or may be a recording medium connected to a photographic film. In addition, the present invention can be used for photographic printing of an image recorded by an electronic still camera. In this electronic still camera, distance information of each ranging area is written to a magnetic floppy together with image data. For example, when displaying an image on a CRT and recording the image on a color paper by a digital color printer, the distance information is read out and used for controlling the exposure amount of each point based on the image data.

Further, the position and the luminance of the main part are recorded in a barcode, but a mark, a character or the like may be used. In particular, the position of the main subject may be represented by an intersection of two orthogonal virtual lines that pass through these marks by marking two sides outside the screen.

〔The invention's effect〕

The present invention having the above configuration records the position of the main subject on the screen at the time of shooting and the brightness of the main subject on a recording medium, reads the information at the time of photo printing, and uses the information to calculate the printing exposure amount. Therefore, even if the part determined to be the main subject is a part of the main subject, such as clothes or the background, the density of the main part is correctly detected, and thereby the main part is properly finished. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a photographic camera having a plurality of ranging areas. FIG. 2 is an explanatory diagram of a photographic film in which the position and luminance of a main subject are recorded in a barcode. FIG. 3 is a schematic view showing an example of a photographic printer. FIG. 4 is an explanatory diagram showing a main part. FIG. 5 is a flowchart showing the procedure of the photographic printing method of the present invention. T1 to T9 Distance measuring area 10 Shooting scene 11 Projection unit 12 Light source 13 Subject 13a Subject image 15 Image sensor 30 Photo lens 33 Photo film 35 ... Barcode recording device 37 ... Position information 38 ... Brightness information 50 ... Barcode reader 54 ... Scanner.

Claims (1)

(57) [Claims] 1. The measured luminance of a main subject and the position of the main subject on a photographing screen are recorded on a recording medium at the time of photographing, and the position and luminance of the main subject are read from the recording medium at the time of photograph printing, and photographing is performed. On the screen, a range defined based on the position of the read main subject is set as a main part, and feature values extracted from the main part are weighted in accordance with the magnitude of luminance. A photographic printing method characterized in that a printing exposure amount is determined by using the method.