JPS62255932A - Detection and processing method for picture information - Google Patents

Abstract

PURPOSE:To quickly detect picture frame edges by measuring the light of a negative film with a two-dimensional image sensor and detecting parts between picture frames at a small picture element pitch of the two-dimensional image sensor to obtain the characteristic of the quantity of light. CONSTITUTION:The light from the negative film in a printing part is received by the two-dimensional image sensor to detect the picture element string output of the negative film. This picture element string output is subjected to A/D conversion to obtain a true digital value. Through the exposure correcting operation of picture frames may be performed at a pitch of rough resolution, unphotographied parts between picture frames are detected at a picture element pitch of fine resolution. A characteristic PC of the quantity of light is obtained from information detected by interpolating the picture element pitch, and a maximum value PM of this characteristic PC is detected. A length l where the quantity of light is reduced from the maximum value PM is obtained. An unphotographed area R between frames on the negative film and frame edges are detected in accordance with this length l. Thus, picture frames are quickly detected and positioned to a prescribed position even if a picture information detector having a low resolution is used.

Description

[Detailed Description of the Invention] (Technical Field of the Invention) This invention detects and processes image information of an original film such as a negative film using an image sensor or the like having relatively low pixel density, and detects edges between image frames. The present invention relates to a method for detecting and processing image information.

(Technical background of the invention and its problems) In a photoprinting device, it is necessary to measure the density of the original film (for example, negative film) in order to determine the printing exposure amount or correction amount. An optical sensor such as a photodiode placed near the optical path measures the average density of the negative film as LATD (Large A).
rea Tans-mittance DenSit
y) I am trying to emit B light.

Image detection using LATD measures the average photometry of a negative film, and does not measure the image intensity of a negative film accurately over the entire screen, so there is a drawback that printing exposure or correction is not reliable. Ta. A device that solved this problem, 7t, was published by the applicant in Japanese Unexamined Patent Application Publication No. 8
No. 0-154244, Japanese Patent Application Laid-open No. 60-151831, Japanese Patent Application Laid-Open No. 80-220325, etc. have been proposed, but if the image density of the image sensor used therein is high, the image sensor and its peripheral circuit. There is a problem that the cost of T is very high, and furthermore, the calculation processing time of exposure +1 kg becomes long. Therefore, for calculations such as exposure (I), it is desirable that the pixel density of the image sensor be relatively coarse.

Furthermore, in the photographic printing apparatus, in order to properly print the frame images of the original film onto photographic paper, it is necessary to accurately position the frames of the original film in the optical frame. For this reason, conventionally, seven notches are provided at the side edges of the original film, and these are detected and positioned using an optical sensor, but when providing the notches, it is necessary to accurately correspond to the frames. The disadvantage is that it requires a lot of effort. Also,
There is also a method of positioning the original film by constantly feeding it at a fixed distance, but this method has the disadvantage that positional deviations accumulate and the accuracy is poor. Furthermore, a method has been proposed in which optical sensors such as photodiodes are arranged according to the shape of the frames of the original film, and the position is determined based on the detection status and order of each optical sensor, but this method requires a structure and control algorithm. It has the disadvantage of being complicated. Furthermore, a slit mask is attached to increase the speed of decomposition, but this has the disadvantage of decreasing sensitivity.

Two patent applications were filed by six people as a device that solved this problem.
No. 198740 and Japanese Patent Application No. 80-1857931, however, the pixel density of the image sensor normally used for this is difficult to accurately detect unless the edges of four image frames, which require extremely high resolution, are detected accurately. This is because transport control cannot be performed.

(Purpose of Issue I4) This Issue II+ was made out of the above-mentioned indignation, and the purpose of this invention is to detect image information of an original film such as a negative film with a relatively low resolution image sensor, and to Another object of the present invention is to provide a method for detecting and processing image information, which processes image information of an original film by increasing the resolution tb, and also detects edges of image frames at high speed.

(Summary of the Invention) The present invention is characterized in that an original film and a sensor move relatively, and the image of the R6i original 2 film is photometered by the sensor, and the original film is moved relative to the pixel pitch of the sensor. By processing the output of the pixel array detected at a small pitch and interpolating the pixel pitch, the light 41
．． The characteristics of this film were determined and it was used for transporting the original film and for Tjlm.

(Embodiments of the Invention) First, a photometry method for a negative film as an original film, which is the premise of the first embodiment, will be explained. Note that detection of a negative film using an image sensor is described, for example, in Japanese Patent Application Laid-open No. Sho Go-188740.

As shown in Japanese Unexamined Patent Publication No. 80-151633.

According to the method proposed by the applicant.

In this invention, as shown in FIG. 1, an image information detection device 10 having a built-in surface scanning type two-dimensional image sensor 11 made of, for example, a CCD is disposed near the negative film 2 in the printing section. The image information of the entire screen is divided into a large number of aligned pixels and detected. In other words, the drive circuit (
(not shown) to the image sensor! By applying a predetermined drive signal to the lens system 1, the two-dimensional image sensor 11 converts the transmitted light of the negative film 2 placed in the printing section into the lens system 12.
For example, as shown in FIG. 2(A), the two-dimensional image sensor 11 divides the entire negative film 2 into a large number of aligned small pixels 21; The entire screen of the negative film 2 can be scanned. Then, as the entire screen is scanned, image signals are sequentially output from the output register section of the image sensor 11, the image signals are sampled and held in a sample and hold circuit, and the held values are converted into digital signals by an AD converter. The digital signal from the AD converter is stored in the memory under the control of the old control circuit as shown in Figure 2 (B).
The arrangement corresponds to the pixel 21 as shown in FIG. Values (tsk, yo cape 7, conversion, etc.

The number of times the data is stored is determined by the number of times the data is stored.

Here, 1. In the detection of the image sensor 11, if the sensor has a high resolution, the edge detection ability of the image frame will be high, but since there are many images, calculation processing such as exposure l-knee will be complicated. .

By the way, the dimension measurement method using an image sensor, for example, a line sensor, is as follows: As shown in Figure tS3, the line sensor 2o! is measured through the lens 21. -, by dividing the image of the object to be measured (direct 1\D) 22 imaged at the slice level SL of the figure A into two parts as shown in the figure B, , the number N (for example, 10
24 to 2048 pixels) is determined, the pixel pitch Pi (for example, 14 to 28 pixels) is determined as constant (ti), NXPi is determined, and the size of the object to be measured 22 is determined by further multiplying by the magnification a of the lens 21. Therefore, this measurement method has the following characteristics.

(1) Measurement time is short (0.5 to 100 milliseconds).

(2) Since there are no moving parts, there is semi-permanent durability.

(3) Wide range of applications for non-contact measurement.

(4) There is no limit to the illumination light as long as it is within the sensitivity wavelength range of the image sensor.

(5) The permissible range of the position of the object to be measured is wide.

From these points, this method is considered to be able to meet the on-line measurements required by modern industry, but since it involves the processes of imaging and photoelectric conversion, it includes causes for various measurement errors. In addition, fundamental issues include measurement accuracy,
There was a drawback that the measurement range was limited by the number of pixels N9 and the pixel pitch Pi. Technological advances in LSI production have led to the miniaturization of pixels, and pixels with a few lpitch have been developed.
When performing arithmetic processing such as exposure correction, it is necessary to perform calculations on the image frames of negative film using a number of small unit resolutions! Pixel division into units of 00 points is generally desirable in terms of characteristics for extracting the features of a picture, is advantageous in terms of cost, and is convenient for high-speed image processing.

In this invention, the pixel pitch of the image sensor is interpolated and read, and the pixel pitch Pi is about 10
The measurement resolution (medium -I of tenths) is 1fiIJ
tL, we have completed the detection of edges between image frames of negative film that can be put to practical use. In other words, when measuring the dimensions of an image using an image sensor, common sense has held that it is impossible to improve the measurement accuracy by L than the pixel pitch. This is a result of the idea that one image reading is done digitally. The pitch interpolation of the detection output of a pixel row in this invention is a method that treats the pixel output as a continuous analog signal and detects minute changes in the output. It has taste. This principle is based on the fact that when the output waveform of the step-like sample-held image sensor is obtained as shown by the solid line RL in FIG.
By creating a waveform like the broken line BL where f bright pixels and N2 dark pixels are read, it is possible to detect ΔN that is more subdivided than one pixel. ΔN is N1
It is also possible to detect the pixel output of number [1] and the pixel output of number [1) in OL+, perform A/D conversion, and find the intersection a with the slice level SL by proportional calculation. However, this makes the circuit complicated, requires time for calculation, and allows minute changes to be made in 1. There are also flaws that are difficult to detect accurately. On the other hand, the method of the present invention allows ΔN to be calculated in real time with a simple configuration.
In other words, pixel outputs are detected at minute pitches as shown by broken lines BL in FIG.

Edges of image frames are detected using statistical methods using interpolated variable distributions. I is based on the interpolated signals indicated by wl, w2, etc. by processing the output of the pixel rows detected on the negative film at a pitch relatively smaller than the pixel pitch.
This is accomplished by detecting the length of the I signal. In FIG. 4, the length of the signal 1 is determined by the following equation.

Wl=N, ・↑◆ΔN−7−↑(N+ + ΔN)
・・・・・・・・・(1) Measure this with clock t and get T = kt ・
・・・・・・・・・If (2) is used, then from equation (+) w, ”kt(N,÷ΔN) ・・・・
...(3). Here, if k is 10, Δ
N is counted to the length on 0.1 stroke to obtain an interpolated measurement value.

Next, the method will be explained in detail.

In this invention: As shown in the JSs diagram, a plurality of storage pixel row data areas M (for example, 11 to g10 no 1
One pixel data is formed on the memory as 0 pixel phase (8 minutes). For example, the pixel data A1 stored in the memory corresponding to the light-receiving pixel PI is the X-th to X-th G as shown in FIG.
2 is M21'''M210. Similarly, the other light receiving pixels are formed by the stored pixel data of 11-1110.

After this storage, as shown in FIG. 7, the pixel row data stored in the memory, that is, the image information detected by interpolating the pixel pitch of the negative film 2, is processed to obtain the light quantity characteristic PC, and the Unphotographed area between 2 frames (
Snuke) Detect R and edges of image frames. in this case,
The maximum value PM of the light quantity characteristic PC is the base light value MA of the negative.
and a threshold value Cv of a predetermined rate (for example, 8 oz). This means that the edge of an image frame of a negative film is at the boundary between the image frame and the unphotographed area, and generally the edge of the image frame is lower than a certain threshold value Cv. This is because the shadow becomes larger. In addition, it is necessary that there is a distance from the position of the maximum (tLPH) of the light quantity characteristic PC at which the light quantity 2- has a negative slope, that is, there is a distance a sentence at which the light quantity decreases from the maximum value PM within a predetermined distance (for example, lam). This is because frame edges exist after passing the snooker R between frames, and it is necessary to remove noise components.The range may have a certain tolerance width, and furthermore, the maximum It is necessary that the light quantity NP in the distance # sentence corresponds to the edge of the image frame from the value PM, and is within a certain ratio range with respect to the maximum value PM.

This means that the amount of light is necessarily smaller than the maximum value PM, and that the slope needs to have a certain degree of variation. This is because if there is not much difference between the light r4MP and the maximum value PM, it is difficult to distinguish between an image and an unphotographed area. In this case, fixed amount and feed are used. In this invention, an edge is detected when all three conditions described above are met. Note that in this example, the true value of the light amount is obtained in 8 bits (0 to 255).

By the way, the edge detection described above is performed as shown in FIG. 8(A), for example.
, (B) and FIGS. 9(A) to (C). That is, in FIG. 8, the amount of time-series change in the pixel row 40 of the image sensor detected with respect to the moving state of the negative film 2 with fine pitch feed as shown in FIG. 8(B) is the same. As shown in Figure (A), the position where the change record becomes zero can be detected as the unphotographed area between the image frames. In addition, in FIG. 9, the sensor outputs of two adjacent pixel columns are shown in (A) and (8), and the difference (B) -
The position n where the change rl+ in the same figure (C) showing (A) becomes zero
can be detected as an unphotographed area between image frames, and when the direction of change is reversed, as an edge of an image frame.

Figure 10 shows one arbitrary negative film (frame No. 1 to 24).
), an example of data regarding the detection error between the edge detection value and the actual measurement value by the above-mentioned algorithm is shown.

In this example, the maximum light in Figure 7! Light whose value of light characteristic PC from direct value PM has decreased by 852 1. Detection of the distance ml at the position t%p (ID? (1st place ll11) Detection error (DT-R
) is shown.

As is clear from this example, the error is approximately ±0.2~0.
This is within the range of 311, and since the positioning and stopping accuracy of frames is normally required to be around ±0.5 cm, this is sufficient for practical use.

By the way, when dynamically controlling the transport of frame images, the frame size of the negative film 2 is known by correction or data input, so the two pixel rows 4o are set in the image information detection area and the frame size. Switch and use as shown in Figure 1+. When all the pixels of image sensor II are composed of j column (1 to 40) and i column (1 to 30),
For example, for 135F size, area F2 is used and 110F size is used.
The area Fl is used for the size. Then, let the measured value of pixel Sii of the image sensor 11 be TS, , and j
Find the true value of the jnth sampling point in the column. 1
In the case of 35F size, the average value T is 23-7 pixels.
= 18, so when detecting negative film 2 at a minute pitch,
135F size antilog id of each adjacent sampling point
TH5+zbr is found by
Since the number of pixels is 19-11-8, when detecting the negative film 2 at a minute pitch, the true number digit 1 of 110 size of each adjacent sampling point (Sth 0 is .

It can be found by (7). When we sample the measured values obtained in this way and obtain the frequency distribution, we obtain an antilogous number of 4 as shown in Figure 7.
1 curve PC is obtained.

Detection of the edges of image frames can be used to control the conveyance of negative film, and an example of this will be described in detail next. Note that the method disclosed in Japanese Patent Application Laid-Open No. 1987402 can also be used.

FIG. 12 is a flowchart showing an example of a method for stopping the detection of image frames. First, a negative carrier of a size corresponding to the size of the negative film 2 to be printed is loaded into a predetermined position of the printing section (Step St), the negative carrier The size of the aperture of the image sensor 11 is measured using the image sensor 11.
Make 8 stitches as in No. 151828 (Step S2)
, Incidentally, this size measurement can be performed by setting the conveyance r- of the negative film 2 according to this size measurement information, automatically selecting and extracting the pixel row 40 described above, and furthermore. is a printed exposure star and its modification 7H:, +,
control.

Next, the negative film 2 to be printed is loaded in a position where the empty frame at the leading end of the negative film almost corresponds to the opening of the negative carrier [step S3], and the leading end of the negative film 2 is placed on the negative drive roller. When the negative film 2 is loaded, the pulse motor is driven to transport the negative film 2 at high speed by a distance s1, which is half the frame interval (step s4), and then to perform slow fine pitch feeding (step s5).

During this time, image information is detected by the image sensor 11, and edges of image frames are detected in a continuous manner. FIG. 13 shows this situation. The negative film 2 is conveyed in the N direction to the printing section of the negative carrier 32, and the unphotographed area RB between the frames is detected by the image information detection device 1o. are doing. The pixel row 40 of the image sensor 11 is located at the center of the opening of the negative carrier 32.

In step 55, the negative film 2 is continuously conveyed at a minute pitch until the edges of the image frames are detected.
) If an edge between one image frame 2A and the unphotographed area RB is detected, the distance fi (S2) from the size information obtained in the size measurement (step S2) to positioning the frame in the printing area is determined. Only high-speed constant S4 conveyance step S
8. S? , S8), and then stops 1- (step S3). In this case, after the high-speed constant IIi transport S1, the image frame 2A located approximately at the center of the negative carrier 32,
fl! until the edge of the unphotographed area RB and image frame 2A between 28 and 28 is detected. #E is a parameter (variable a) that corrects variations in the distance of the two-legged unphotographed region RB,
Sending image frame 2A in the state shown in Fig. 13:: D -S
l◆E-8? If the negative film 2 is conveyed, the image frames of the negative film 2 will eventually stop (1-) in a state where they are accurately positioned in the printing section.

After the conveyance number of the negative film 2 is stopped, it is determined whether the stopped F frame is suitable for printing or not in step 5I.
O) If it is not suitable for printing, skip to step S12, and if it is suitable for printing, print the stopped frame at the determined exposure destination and correction 25 (step 5ll).
), in order to convey the next image frame to the printing section and print it after the completion of printing of the frame, it is determined whether or not there is still negative film A 2, and the negative film 2 is transferred according to the size information obtained in step S2 above. By conveying the image at a high speed by a little less than 1 to 2 frame intervals (step S!2° S4), and repeating the above-described conveyance and stopping, it is possible to automatically print each image frame in sequence. Then, in step S12, when the negative film 2 becomes focused, the idling of the negative drive roller is automatically stopped and the process ends. Here, detection is performed at the center of the negative film located in the first carrier, but this does not prevent detection near the center (or near the periphery).

In addition, in 1-description, the pixel column data area to be stored in the memory is set to "10 columns" for each light-receiving pixel column, but it can be set to any number. Also, 1 of the detection area in Figure 11
1st row is also changed to 5r moat. Furthermore, although the description in the above is based on the amount of light in terms of true values, it is also possible to process in terms of density values.

(Effects of the Invention) As described in I-I, according to the method of this invention, high resolution can be achieved even by using a relatively low resolution sensor, and image frames can be automatically detected and positioned at predetermined positions. Moreover, it can be performed at high speed, and efficient and reliable photographic processing can be realized. Furthermore, even though the edge detection conditions are set to simple identification conditions (algorithm), it is difficult to realize accurate edge detection.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the case where the present invention is applied to a photo printing device, and FIGS. 2 (A) and (B) illustrate an example of the correspondence between pixel division of an original film and stored data. Figures 3 and 4 are diagrams for explaining the principle of this optical IJ1, and Figures 5 and 6 are diagrams for explaining the relationship between detected data of a pixel column and storage in a memory according to the present invention. figure. Fig. 7 is a diagram showing an example of the relationship between negative film and memory detection data, Fig. 8 (A), (B), and Fig. 9 (
A) to (C) are diagrams each showing how edge detection is performed, FIG. FIG. 12 is a flowchart showing an example of the operation for stopping image frame detection, and FIG. 13 is a diagram showing the state of the negative carrier section. 2... Negative film, 3... Filter, 4... Light source, 5, 11... Lens system, 6... Black shutter, 7... Photographic paper, 8... Light sensor, 10・
...Image information detection device, 30...Film transport device. Applicant's agent Yu Yasugata 3φ~4th;'Figure S7゜(A) <B) Broom 2 figure & gong! Jll Pa/s2 *3 #4 x5 m6
g7 $θ #Q #L0 Figure 0 Early 13 En 12th Procedural Amendment 6.1 Commissioner of the Patent Office Black 1) Ming fIn Hit 1, Display of the case 1985 Patent Application No. 99878 2, Title image of the invention Information detection and processing method 3, relationship with the amendment person case Patent applicant (520) Fuji Photo Film Co., Ltd. 4, embedded content of Yamamasa, Nishi-Shinjuku-chome 14-15, I-Shuku-ku, Tokyo] l) The word "extremely" on page 5, line 12 of the specification is deleted. :2) Same, page 20, line 3, "(52) J"
S2” is corrected. ]3) Same, page 23, line 9, r5. IIJ and aruo r
s, 12J.

Claims (5)

[Claims] (1) The original film and the sensor move relatively, and the image of the original film is photometered by the sensor, and the pixel rows of the original film are detected at a pitch relatively smaller than the pixel pitch of the sensor. A method for detecting and processing image information, characterized in that a light amount characteristic is determined by processing the output and interpolating the pixel pitch, and the light amount characteristic is used for controlling the conveyance of the original film. (2) the maximum value of the light quantity characteristic is between the base light quantity value of the original film and a first threshold value;
The negative slope of the light amount characteristic is continuously within a predetermined distance range, and the light amount at the predetermined distance is within a range of second and third threshold values based on the maximum value of the light amount characteristic. 2. The method for detecting and processing image information according to claim 1, wherein edges of image frames of the original film are detected by the determination. (3) The image information detection and processing method according to claim 1, wherein the sensor also serves as a sensor for determining or correcting exposure amount. (4) The image information detection and processing method according to claim 1, wherein the sensor is an image sensor. (5) The original film and the sensor move relatively, and the image of the original film is photometered by the sensor, and the original film is detected by a single pixel row or a plurality of pixels at a pitch smaller than the pixel pitch of the sensor. 1. A method for detecting and processing image information, characterized in that the edges of image frames of the original film are detected by processing output of columns.