JPH0278380A - Picture processor - Google Patents

Abstract

PURPOSE:To extract only a picture corresponding to a person from an object by providing a heat ray sensing means sensing a heat ray from an object and an extraction processing means processing a picture signal by a picture conversion means and a heat ray sensing signal by the heat ray sensing means, processing only the part of the object radiating the heat ray from the object as a picture and outputting the result. CONSTITUTION:A picture of the object 5 is formed on a CCD image sensor 8 through a conductor lens 7, amplified by an amplifier 9 and converted into a digital signal by an A/D converter 10. On the other hand, a picture of the object 5 is formed on a 2-dimension sensor 13 through an infrared-ray lens 12, amplified by an amplifier 14 and converted into a digital signal by an A/D converter 15. Then a binarizing processing circuit 16 taking an infrared-ray power of the image of a portrait 5a as a threshold level applies binarizing processing in a way that the level of the background is all 0 and the level of the portrait is logical 1. Then the result is ANDed by an AND gate 17 to make the picture data of the portrait 5a only effective and a portrait extracted picture is obtained at an output terminal 19.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image processing apparatus for equipment that mainly handles images of people, such as video telephones.

Conventional technology In general, images of people are required information for videophone calls.
A background image is often not necessary.

For example, FIG. 6 schematically shows the videophone 1, so
First, an image of a person or the like is photographed and read using the image pickup tube 2, and the image is displayed on the other party's CRT via a communication line. The person on the other end is displayed on the CRT 3 of the own videophone 1.

FIG. 7 shows an example of the object 4 projected on the CRT 3. In FIG. 7, 4a is an image of a person, 4b is an image of a door, and 4c is an image of a clock.

Here, generally the required image is the person 4a,
In many cases, other background images such as the door 4b and clock 4c may not be necessary, and in many cases, it is sufficient to understand only the atmosphere of the background image.
In extreme cases, it may be a background image that you do not want people to see. In particular, for videophones installed in laboratories, laboratories, etc., it may be desirable not to show the background to maintain confidentiality.

Problems to be Solved by the Invention However, in the conventional device, all images taken by the image pickup tube 2 are displayed on the other party's CRTa.

In addition, in the case of videophones, etc., there is a limit to the information transmission speed through the transmission line, so generally the data is compressed and encoded using a block encoding method, etc., and then transmitted.
If the compression rate is increased, image results such as block noise and blurring will occur.

Means for Solving the Problems In the invention as set forth in claim 1, in an image processing apparatus equipped with an image conversion means for converting an object into an image, a heat ray detection means for detecting heat rays from the object is provided, and the image conversion An extraction processing means is provided for processing the image signal from the means and the heat ray detection signal from the heat ray detection means, and outputting an image of only the object that emits heat rays.

In the invention as claimed in claim 2, the image signal by the image converting means and the heat ray detection signal by the heat ray detection means are processed, and the code amount of the object that does not emit heat rays is reduced to the code amount of the object that does not emit heat rays. An encoding means for performing different encoding processes is provided.

Further, in the invention according to claim 3, in addition to the heat ray detection means for detecting the heat rays from the object, a motion detection means for detecting the movement of the object is provided, and the image signal from the image conversion means and the heat ray detection means are An extraction processing means is provided which processes the motion detection signal from the motion detection means together with the heat ray detection signal and outputs an image of only the object that emits heat rays and moves within the object.

Furthermore, in the invention according to claim 4, an image storage means is provided in which image information other than the object to be imaged by the image conversion means is stored in advance, and the image signal from the image conversion means and the image signal from this image storage means are provided. An image synthesis processing means is provided which performs synthesis processing to switch between the images and the images according to a heat ray detection signal from the heat ray detection means and outputs the resultant image.

The action image conversion means grasps not only the person but also the entire object including the background. On the other hand, when comparing a background object and a person, the person generally emits stronger infrared heat rays. Therefore, according to the heat ray detection means of the invention set forth in claim 1, only an image corresponding to a person can be extracted from the object. As a result.

By performing processing using the extraction processing means using both signals,
Output of extracted human images only can be obtained.

On the other hand, if the heat ray detection means is used in this way, it is possible to distinguish between a person image in an object and a background image, so that signal processing for transmission can also be made different. Therefore, according to the invention as claimed in claim 2, the encoding processing means performs encoding processing such that the amount of code for the background image portion is smaller than the amount of encoding for the person image portion. Encoding processing with a high overall compression rate is possible without deteriorating the image.

By the way, when only a heat ray detection means is used, if a background object includes an electric light or the like, it emits heat rays and is therefore detected in the same manner as a person, resulting in an image of a person and a heat ray background object such as an electric light. In this respect, as in the invention described in claim 3,
By providing a motion detecting means in addition to the heat ray detecting means, and performing processing by the extraction processing means in consideration of the motion detection signal, it is possible to obtain an output in which only images of people who move and emit heat rays are extracted.

Moreover, when only the person image extracted based on the heat ray detection means is output, there is no background image, which may give an unnatural impression. In this respect, as in the invention as claimed in claim 4, image information other than the object to be imaged by the image converting means is stored in advance in the image storage means, and the person from whom this stored image is extracted By performing compositing processing with images, it is possible to provide a natural-looking human image with a background image different from the actual background.

Embodiment An embodiment of the invention set forth in claim 1 will be described based on FIG. First, as in the case of FIG. 7, an image converting means 6 is provided for photographing and converting images of a person 5a and various other objects such as a door 5b and a clock 5c. According to FIG. 6, this image conversion means 6 corresponds to the image pickup tube 2, and is composed of a condenser lens 7, a COD image sensor 8, an amplifier 9, and an A/D converter 10. That is, the image of the object 5 is formed on the CCD image sensor 8 by the condensing lens 7, photoelectrically converted, and read as an electrical signal. After this signal is amplified by amplifier 9,
The A/D converter 10 converts the signal into a re-digital signal. The object 5 read by the image conversion means 6 in this way
If the image is left as it is, the image will be as in the case of FIG.

On the other hand, in this embodiment, in addition to the image conversion means 6, a heat ray detection means 11 is provided. This heat ray detection means 11 includes an infrared lens 12, a two-dimensional sensor 13, an amplifier 14, and an A/D
It consists of a converter 15 and a binarization processing circuit 16. That is, an image of the object 5 is formed on the two-dimensional sensor 13 by the infrared lens 12. At this time, the image formed on the two-dimensional sensor 13 is an image based on the properties of infrared rays. Here.

Infrared rays are emitted from all objects that have a temperature, and the infrared power W is expressed by the Stefan-Boltzmann formula % (%). Here, σ; Stefan-Boltzmann coefficient (= 5.65 x 10-"W/cm-deg')
T is the absolute temperature (K).

In other words, it can be seen that infrared rays are emitted more strongly from objects with higher temperatures. Therefore, it can be said that the image of the person 5a in the object S emits infrared rays more strongly than the images of the door 5b, clock 5c, etc. in the background. Then, the signal photoelectrically converted by the two-dimensional sensor 13 is amplified by the amplifier 14, and then A/D
The converter 15 converts it into a digital signal. Next, a binarization processing circuit 16 that uses, for example, the infrared power of the image of the person 5a as a threshold, converts the background to all 0 and the person to 1.
Binarization processing is performed as shown below. Therefore, the digital signal output from this binarization processing circuit 16 is
This data indicates the area corresponding to the image (this data alone cannot display the details of the person).

Therefore, the A/D converter 10 of the image conversion means 6
An AND gate 17 serving as an extraction processing means is provided in order to perform a process of logically multiplying the image signal from the heat ray detection means 11 with the heat ray detection signal from the binarization processing circuit 16 of the heat ray detection means 11. This AND gate 17 is for outputting only the object emitting heat rays in the object 5, specifically, the person 5a, as an image signal. That is, the image read by the image conversion means 6 includes all the objects 5,
a, 5b, 5c, etc., but only the image data of one person 5a becomes valid by performing a logical product with the signal from the binarization processing circuit 16 indicating the area of the person image, and 1
A person extraction image as shown at 8 is obtained at the output terminal 19.

From the perspective of the door 5b, the clock 5C, etc., this means that the masking process has been performed.

The image signal of the person extracted image 18 from the output terminal 19 is encoded by the encoding circuit 20 to a bit rate suitable for the transmission medium, and then transmitted and outputted by the transmitter 21.

On the other hand, on the other party's side, the receiver 22 receives this signal, the decoding circuit 23 decodes it, and the D/A converter 24 converts it into an analog signal. Then, after being amplified by the amplifier 25, it is displayed on the screen of the CRT 26. This display image is an image of only a person without a background image.

Next, an embodiment of the invention according to claim 2 will be described with reference to FIGS. 2 and 3. This example is based on the AN of the previous example.
In place of the D gate 17 or the encoding circuit 20, an encoding device 27 serving as encoding processing means is provided. This encoding device 27 does not uniformly compress and encode the entire object, but only objects that do not emit heat rays,
That is, the encoding process for a background image is different from the encoding process for an object that emits heat rays, that is, a portrait image, and the compression process is performed so that the amount of code for the former is smaller than the amount of code for the latter. For example, the portrait image extracted from the object by the method of the embodiment is subjected to normal encoding, while the remaining background image is encoded at a high compression rate using a block encoding method or the like.

Here, an example of processing by this encoding device 27 will be explained in detail. First, as in the case of the above embodiment, the person 5a
Binarization processing circuit 1 that uses the infrared power of the image as a threshold value
6, a binarization process is performed such that the background is all 01 and the person is 1, and the result is input to the encoding device 27. on the other hand,
The image of the object 5 is focused on the COD image sensor 8 by the condensing lens 7, charged and converted, read as an electrical signal, amplified by the amplifier 9, and then converted into a digital signal by the A/D converter IO. It is converted and input to this encoding device 27. With the help of these two people, person 5
It is possible to extract only the a image, and the A/D converter 10
Among the image data obtained from the A/D converter 10, the human image region in which the output of the binarization processing circuit 16 is 1 is subjected to normal encoding processing for transmission, and the image data obtained from the A/D converter 10 is converted into a binary image. The remaining background image regions where the output of the encoding processing circuit 16 is O are encoded with a small amount of code.

In this embodiment, block encoding is used.

This block encoding method will now be explained. By the way, the block coding method itself is described in the paper ``Differential Adaptive Block Coding Method for Grayscale Images'' (Transactions of the Institute of Electronics, Information and Communication Engineers '87/l VOQ).

J70-B No. 1). In this method, an image is first divided into blocks each consisting of m×m pixels, the maximum and minimum gradation levels within the block are determined, and the range between the maximum and minimum values is quantized into 2n gradations. Then, the shells of gradation levels within the block (if n=2, φ1.φ,) are obtained, and the 6 difference values and bit brain information to be transmitted are simplified as follows. Here, the case where n=2 will be explained as an example.

First, two threshold parameters THL and TH2 (THI≦TH2) for the difference value are set. Then, in mode A: a block where 2Lo<THI, the inside of the block is expressed in rubels. That is, LA represents the gradation level, and L
D=0, φ1. φ2=fixed.

Mode B: A block where TH1≦2LD<TH2 is expressed in two levels. In other words, the bit plane information is expressed only by φ1, and φ2 is fixed.

Mode C: Blocks with TH2≦2LD are φ1゜φ2
It is expressed in 4 levels.

For example, in Figure 3, LA+ of a block consisting of 4 x 4 pixels
LDr φ1. An example of finding φ2 will be shown. Same figure (
In a), individual A/D conversion data is shown for each 4×4 pixel block. In this case, LMAx=41, LMrN
= 17, so the difference value 2・LD is LMAX
LMIN=24. In this case, if THI=26, since 2.LD<THI, it becomes mode A, and L^=29. LD=O1φ1. φ2=O, and all pixels in the block are represented by LA as shown in mode A in FIGS.

Also, if TH1=lO1TH2=30, mode B
becomes. As a result, as shown in mode B in the same figure (C), O is assigned to all blocks of φ2, while φ1
As shown in mode B in the same figure (b), O is assigned to pixels with LA=29 or more in the block, and LA
The following pixels are assigned l. That is, LA+(L.

/2) and LA (Lo/2).

Furthermore, in the case of TH2=23, since TH2≦2·LD, the mode becomes C, and φ1. Figure 3 (b) is used for φ2.
) (C) As shown in mode C, each pixel is
is assigned, and the pixels within the block are LA+(3・LD
/4), LA+ (Lo/4), LA (Lo/4)
, LA (3・Lo/4).

Of the information obtained in this way, LA encodes the difference from the value in the previous block with a variable length code, while LD encodes the value as it is with a variable length code.・Also, φ1
．． Regarding φ2, each pixel is encoded as a bit-brain image using a two-dimensional encoding method, which is a standard encoding method for binary images. Such a two-dimensional encoding method is known as a data compression method in the facsimile transmission method.

By the encoding method as described above, the A/D converter 10
At this time, the binary output obtained from the binarization processing circuit 16 is referred to. First, when all the pixels in the coding block corresponding to the binary output from the binarization processing circuit 16 correspond to O, the block is regarded as a background part and is coded with a small amount of code, that is, in mode A. Then perform the encoding process. In contrast,
If the binary output from the binarization processing circuit 16 contains 1 in the corresponding encoded block, it is regarded as a human image, and normal block encoding is performed.

In this way, since the background image is encoded in mode A, the amount of code = amount of transmitted information can be reduced. That is, the code amount of LA is the same as modes B, C, etc., but regarding the code amount of LD, the variable length code used for LD is a value of O such as WYLE code, or a code whose code length is shorter than other values. By using , the amount of code is reduced. Also, φ1. Since φ uses a two-dimensional encoding method, in mode A, all blocks in the block are O's, long runs occur in the vertical and horizontal directions, and the data compression rate becomes high.

As a result, according to this embodiment, the human image is reproduced without deterioration because the required amount of information = amount of code is ensured, encoded, and transmitted. On the other hand, because the background image side is encoded with a smaller amount of code, a higher compression rate can be achieved under the constraints of information transmission speed than when the entire object is encoded with a uniform amount of code equivalent to a human image. can. Here, the reproduced image of the background image may be blurred, but this is not a problem because the atmosphere of the background image can be seen better than that of a portrait.

Next, an embodiment of the invention according to claim 3 will be described with reference to FIG. As in the embodiment described above, the heat ray detection means 11
If only the object 5 shown at the left end in Fig. 4 is provided,
If an electric lamp 5d is present in place of the clock 5C, as in the example shown in FIG. includes an electric light image 29d as well as a human image 29a. Therefore, as mentioned above, this output and A/
When ANDed with the image output from the D converter 10,
This includes the electric light image 29d, and it is not possible to extract only the human image 29a. That is, in the background image, things such as the door 5a can be masked, but things that emit heat rays, such as the electric light 5d, cannot be masked.

Here, when looking at the background image such as the electric light 5d and the person 5a, the person 5a generally moves, whereas the electric light 5d and the like are stationary. Therefore, in this example,
In addition to the heat ray detection means 11, a means for detecting movement in the object 5 is provided, and the movement detection signal is also used for processing, thereby masking a heat ray image such as the electric lamp image 29d and masking the human image 29a. It allows you to extract only the For this reason, specifically, as shown in FIG.
One frame delay memory 30 on the output side of the D converter 10
and a comparator 31 that compares the signal that has passed through the one-frame delay memory 30 with the signal that has not passed through the one-frame delay memory 30.
It has been established.

The motion detection signal from the comparator 31 of the motion detection means 32 and the heat ray detection signal from the binarization processing circuit 16 of the heat ray detection means 11 are input to the human area determination device 33; The output is the A/D of the image conversion means 6.
AND gate 1 along with the image signal from converter 10
7 is entered.

In such a configuration, the digital signal converted into digital by the A/D converter 15 of the heat ray detection means 11 as in the embodiment described above is converted into a digital signal by the binarization processing circuit 16 with an appropriate threshold value, such as the person 5a or the like. A binarization process is performed in which the object having a high temperature and emitting heat rays, for example, the electric light 5d, is set to 1 and the normal background is set to 0. Therefore, the digital signal output from this binarization processing circuit 16 becomes the heat ray image 29 including the human image 29a and the electric light image 29d as described above (it is not possible to display the entire image with only these data). ).

On the other hand, the image signal from the A/D converter 10 of the one-image conversion means 6 is input to the one-frame delay memory 30, and the image delayed by one frame and the current image are input to the comparator 31. Therefore, image data based on the current frame data and image data based on data delayed by one frame are input to the comparator 31, and the density difference between the two data is calculated for each pixel. Through such a comparison, a density difference appears in moving images, but no density difference appears in static images, and it is possible to extract moving images. In this example, the comparator 31
A motion detection signal is output from. The motion detection signal from the comparator 31 is input to the human area determination device 32 together with the heat ray signal from the binarization processing circuit 16. This person area determination device 32 detects a human image 29a with movement from the heat ray image 29.
Only this human image 29a area is determined to be a human area, and only this human image 29a area is set as 1, and the other areas, including the electric light image 29d, are output as 0.

Then, the AND gate 17 calculates the logical product of the direct image signal from the A/D converter 10 of the image converting means 6 and the binary signal from the human area determiner 32. This AND gate 17 is for outputting only the object in the object 5 that emits heat rays and is accompanied by movement, specifically, the person 5a, as an image signal. That is, the image read by the image converting means 6 is the object 5.
The human area determination device 32 processes the heat ray signal from the binarization processing circuit 16 indicating the area of the human image and the motion detection signal from the comparator 31. By taking the AND with the signal from
Only the image data of the person 5a becomes valid, and a person extracted image as shown at 18 is obtained at the output terminal 19. Not only the door 5b but also the electric light 5d that emitted the heat rays can be seen to be masked.

Further, an embodiment of the invention set forth in claim 4 will be explained with reference to FIG. For example, in the case of the invention described in claim 1 or 3, the background image is completely masked and only the human image remains, resulting in a blank background, which may give an unnatural impression. Therefore, in this embodiment, an image memory 34 is provided as an image storage means that stores in advance an image 33 that is different from the actual object 5 handled by the image conversion means 6, for example, an image 33 including a door 33a and a window 33b. The image signal stored in the image memory 34 is combined with the image signal from the A/D converter 10 of the image conversion means 6 and the heat ray signal (binarized signal) from the binarization processing circuit 16 of the heat ray detection means 11. , are input to a multiplexer 35 serving as an image synthesizing means. At this time, the image signal for one screen from the image memory 34 is controlled by the address counter 36 so as to be synchronized with the image data from the A/D converter 10.

In such a configuration, the image converting means 6 and the heat ray detecting means 11 process the object 5 in the same manner as in the embodiment described above. That is, the A/D converter 10 obtains an image signal for the entire object 5, and the binarization processing circuit 1
6, a heat ray detection signal (binarized signal) only for the person 5a emitting heat rays is obtained, and these signals are manually input to the multiplexer 35, while another image 3 stored in the image memory 34
The data for one screen of No. 3 is input to the multiplexer 35 in synchronization with the image data from the A/D converter 10 by the address counter 36.

In this multiplexer 35, image data from the A/D converter 10 is assigned to a portion where the binary signal from the binary processing circuit 16 is 1, and in this example, it becomes a human image. This processing corresponds to the processing by the extraction processing means of the embodiment described above. On the other hand, image data from the image memory 34 is allocated to the background portion where the binary signal from the binary processing circuit 16 is O. As a result, the output terminal 37 of the multiplexer 35 receives the human image 5a.
A composite image 38 is obtained by combining the image 33 and the image 33. This is more natural than an image of only a human figure. The background image at this time is not an actual background but a fictitious one stored in the image memory 34 in advance, so there is no problem in terms of confidentiality.

Effects of the Invention Since the present invention is configured as described above, according to the invention as set forth in claim 1, a heat ray detection means for detecting heat rays from an object is provided, and the image signal by the image conversion means and the heat ray detection are Since the heat ray detection signal and the heat ray detection signal are processed by the extraction processing means and only the object emitting heat rays in the object is output as an image, it is possible to display only a portrait of the person on the other end during a videophone call, etc. secrecy can be maintained using background images, etc.

According to the invention as claimed in claim 2, the image signal by the image converting means and the heat ray detection signal by the heat ray detection means are processed, and the code amount of the object that does not emit heat rays is compared with the code amount of the object that emits heat rays. Since we have provided an encoding means that performs different encoding processes with a small amount of code, when considering the transmission of image information, it is possible to reduce the deterioration of human images compared to when the entire image is compressed and encoded uniformly. The entire data can be encoded at a high compression rate to fully satisfy the information transmission rate standard.

According to the third aspect of the invention, in addition to the heat ray detection means, a motion detection means for detecting the movement of the object is provided, and this motion detection signal is also processed by the extraction processing means. Even if there is a background object that emits heat rays, such as an electric light, in the object, this can be distinguished from a moving human image and masked, and only the human image can be extracted and displayed.

Furthermore, according to the invention set forth in claim 4, an image storage means is provided in which image information other than the object to be imaged by the image conversion means is stored in advance, and both image signals are subjected to heat ray detection by the image synthesis processing means. Since the synthesis process is performed by switching the selection based on a signal, it is possible to display a natural image by combining an image different from the actual background image with the image of a person emitting heat rays in the object, and, This allows the confidentiality of the actual background image to be maintained.

[Brief explanation of the drawing]

FIG. 1 is a conceptual block diagram showing an embodiment of the invention as claimed in claim 1, FIG. 2 is a conceptual block diagram showing an embodiment of the invention as claimed in claim 2, and FIG. 3 is a code thereof. FIG. 4 is a conceptual block diagram showing an embodiment of the invention as claimed in claim 3; FIG. 5 is a conceptual block diagram showing an embodiment of the invention as claimed in claim 4. , FIG. 6 is a schematic side view of a general video telephone, and FIG. 7 is a front view showing an example of a CRT screen display thereof. 5... Target object, 5a... Extraction target object, 6... Image conversion means, 11... Heat ray detection means, 17... Extraction processing means, 27... Encoding processing means, 32. ...Motion detection means, 33...Another image, 34...Image storage means, 35...Image synthesis processing means Applicant Ricoh Co., Ltd. J Must Figure 36 Figure J Figure 37

Claims (1)

[Scope of Claims] 1. In an image processing apparatus equipped with an image conversion means for converting an object into an image, a heat ray detection means for detecting heat rays from the object is provided, and the image signal from the image conversion means and the heat rays are 1. An image processing device comprising an extraction processing means for processing a heat ray detection signal from a detection means and outputting an image of only an object that emits heat rays. 2. In an image processing apparatus equipped with an image conversion means for converting an object into an image, a heat ray detection means for detecting heat rays from the object is provided, and an image signal from the image conversion means and a heat ray detection signal from the heat ray detection means are provided. 1. An image processing apparatus comprising an encoding means for processing an object that does not emit heat rays with a different encoding process using a smaller amount of code than an object that emits heat rays. 3. An image processing device equipped with an image conversion means for converting an object into an image, including a heat ray detection means for detecting heat rays from the object and a movement detection means for detecting movement of the object, Extraction processing means for processing an image signal by the conversion means, a heat ray detection signal by the heat ray detection means, and a motion detection signal by the motion detection means, and outputting an image of only the object that emits heat rays and moves within the object. An image processing device comprising: 4. An image storage means is provided in which image information other than the object to be imaged by the image conversion means is stored in advance, and the image signal from the image conversion means and the image signal from the image storage means are transmitted to the heat ray detection means. 4. The image processing apparatus according to claim 1, further comprising an image synthesis processing means for performing a synthesis process and outputting the resultant image by switching based on a heat ray detection signal.