KR101469984B1 - Apparatus for image processing and method for initializing image processing - Google Patents

Abstract

The present invention relates to a camera image processing apparatus and an image processing initialization method, and is characterized in that characteristic values of a camera module are recorded in a camera module, and these characteristic values are read to initialize a video signal processor. The present invention relates to a camera module including a camera module having a characteristic value storing unit for storing characteristic values indicating the performance of a lens and an image sensor, and a control unit for reading the characteristic values stored in the characteristic value storing unit, And a video signal processor (ISP). The characteristic values include Date and Line (production date and production line), Depth of field, EPL (effective focus distance), BFL (distance between the image sensor and the last lens), F number ), Max stroke, Start Code, Stroke of minimum step, Cut-off Frequency, Cutoff frequency of the infrared filter, Lens At least one of the characteristic values indicating the performance of the shading data, the hot-pixel data of the image sensor, the resolution, and the operation time of the camera module One or more.

Camera, image sensor, lens, actuator, module, initialization, tuning, performance

Description

Technical Field [0001] The present invention relates to a camera image processing apparatus and an image processing method,

The present invention relates to a camera image processing apparatus and an image processing initialization method.

A camera module is embedded in a terminal such as a digital camera, a mobile phone, a smart phone, a PDA (Personal Digital Assistant), and a DMB (Digital Multimedia Broadcasting) phone.

Therefore, in order to distinguish the camera module from a large number of hundreds to several thousands, a production lot (LOT) is indicated on the corresponding camera module when the manufacture and production of the camera module are completed. The above-mentioned production lot is a level in which only the product number and the production date are coded and displayed.

1, the image sensor 12 converts an optical image received through the lens 11 into a video signal and outputs the converted video signal to the video signal processor 20 (FIG. 1). ISP). The video signal processor 20 controls the camera module to correct the received video signal to improve the image quality.

The camera module 10 has a performance as a sensing standard for a predetermined image level, phase, shading, and contrast. In general, (10) have different characteristic values. That is, in a situation where a high image quality is required in a high image quality, the performance of the camera module is significantly influenced by variations in the characteristics of a lens, an image sensor, and an actuator, Deviation of characteristic value) tends to widen the distribution.

Therefore, the manufactured camera module passes through the inspection process and checks whether the characteristic value of the corresponding camera module is within the reference range. For this purpose, the camera module is connected to the inspection system and the image is evaluated and the characteristic value is derived.

However, the characteristic values derived from the inspection process are not stored or marked separately. This is because it is impossible to recognize all deviations between the camera modules only in the production lot notation. As a result, only the product number and the production date are coded and displayed in the production lot (LOT) indicated by the camera module after the manufacture and production of the camera module is completed, and the characteristic value of the corresponding camera module derived from the inspection process can not be displayed there is a problem.

Meanwhile, in the case of the image signal processor 20 that receives image signals from the image sensor 12 and performs image quality improvement, an initialization operation of an image signal processor (ISP) is performed. Currently, several hundreds to several thousands Since representative values of each camera module are used, accurate image quality improvement is not possible for each camera module. That is, the camera module has different characteristic values for each module. Since the image signal processor uses the average representative value instead of the characteristic value of the corresponding camera module as the initialization setting value of the camera, accurate image quality is improved for each camera module There is a problem that does not support.

In the present invention, when the initialization of the video signal processor is performed, the initialization using characteristic values unique to the camera module is performed.

The present invention relates to a camera module having a lens and a separate characteristic value storage unit for storing characteristic values indicating the performance of the image sensor, and a camera module for reading the characteristic values stored in the characteristic value storage unit, And a video signal processor (ISP) for controlling the video signal processor.

The image signal processor writes and reads characteristic values of the characteristic value storage unit through a control bus connected between the camera module and the image signal processor.

The characteristic values include Date and Line (production date and production line), Depth of field, EPL (effective focus distance), BFL (distance between the image sensor and the last lens), F number ), Max stroke, Start Code, Stroke of minimum step, Cut-off Frequency, Cutoff frequency of the infrared filter, Lens At least one of the characteristic values indicating the performance of the shading data, the hot-pixel data of the image sensor, the resolution, and the operation time of the camera module One or more.

According to another aspect of the present invention, there is provided a method for controlling a camera module, the method comprising: deriving a characteristic value indicating a performance of the camera module; storing the derived characteristic value in a characteristic value storage unit in the camera module; And reading the characteristic value and initializing it as the characteristic value.

After the manufacture of the camera module is completed, the characteristic values derived from the inspection process are stored in the characteristic value storage unit. After the initialization is performed, the video signal processor writes information related to the driving of the camera module in the characteristic value storing unit.

The present invention relates to a camera module which aims at high picture quality and high image quality and which is equipped with a memory, which is a characteristic value storing section, and is used for a production date of each module, a performance of a lens derived from a production line, Writing characteristic values in the memory to perform history management and characteristic management of the camera module in the future. In addition, it is possible to generate optimal image quality by performing initialization according to the individual performance of each camera module using the feature value, and the defect rate due to the performance deviation can be drastically reduced.

Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. It should be noted that the same reference numerals are used to denote the same or similar components in the drawings.

2 is a block diagram of a camera image processing apparatus according to an embodiment of the present invention.

The camera module 10 includes a lens 11, an image sensor 12 and a characteristic value storing unit 13. The image sensor 12 converts a light image coming from the lens 11 into a video signal, To the signal processor 20 (ISP). The image sensor 12 and the video signal processor 20 are connected to each other via a video signal bus and a control bus so as to transmit a video signal through the video signal bus and exchange control signals through a control signal bus do. Since the data is transferred between the characteristic value storage unit 13 and the video signal processor 20 using the conventional control signal bus, no additional interface bus is needed.

The present invention further includes a memory in the camera module 10, which is a characteristic value storage unit 13 for storing characteristic values of the image sensor. The characteristic value storage unit may be a rewritable memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory.

The characteristic value stored in the characteristic value storage unit 13 is a characteristic value derived from the inspection process of each camera module. For example, the characteristic values are listed in Table 1 below.

[Table 1]

division Attribute Value Item Length 1. Production
Date 8byte Line 2byte
2. Lens

Depth of field 8byte Effective Focus Length (EFL) 8byte Back Focus Length (BFL) 8byte F number 8byte
3. AF actuator
Max stroke 8byte Start code 8byte Stroke of minimum step 8byte 4. IR cut-off filter 꼬트 오프 오프 주파수 8byte 5. Image Sensor Lens Shading Data 16 Kbytes Hot-Pixel Data 1Kbyte 6. Module Resolution 8byte 7. Other Operation Time 256 bytes

These characteristic values are derived from the tuning operation of the camera module, and the above items will be briefly described as follows.

DF is the distance between the image sensor and the last lens, F number is the F number of the camera, Max stroke is the maximum lens distance, The start code is the initial motion code of the actuator, the stroke minimum step is the minimum movement code interval of the actuator, the cut-off frequency is the cutoff frequency of the infrared filter, the lens shading data is the shade of the shade of the lens Hot-pixel data is the hot pixel position of the image sensor, Resolution is the resolution, and Operation Time is a characteristic value indicating the total operation time of the camera module.

These characteristic values are derived from the inspection process of the camera module and written into the characteristic value storage section. The Operation Time item is an item to be directly recorded in the image signal processor, not in the inspection process. That is, the video signal processor detects the time when the camera module is driven, and the video signal processor records the total operation time in the operation time item of the characteristic value storage unit.

The image signal processor 20 reads the characteristic value stored in the characteristic value storage unit 13 and performs an initialization of an image signal processor (ISP). The initialization of the video signal processor is required to control the camera module, thereby improving the image quality. The image signal processor 20 reads and corrects characteristic values inherent to the corresponding camera module 10, thereby achieving precise control by correcting the image quality. In addition, the image signal processor 20 not only reads the characteristic value from the characteristic value storage section but also writes information related to the driving of the camera module (for example, the total operation time of the camera module) can do.

Conventionally, initialization work has been performed with representative values of a number of camera modules, and accurate image quality has not been improved for each camera module. However, as in the present invention, characteristic values for each camera module are read and initialized, Image quality improvement can be achieved.

3 is a flowchart illustrating a camera image processing initialization process according to an embodiment of the present invention.

When the manufacture of the camera module is completed, a characteristic value indicating the performance of the camera module in the inspection process of the camera module is derived (S31).

As shown in Table 1, the characteristic values derived from the inspection process indicate the performance of the lens, the performance of the image sensor, and the performance of the AF actuator. As shown in Table 1, the Depth of field, EPL, BFL, , Start Code, Stroke of Minimum Step, Cut-off Frequency, Lens Shading Data, Hot-Pixel Data, and Resolution.

The characteristic values of the camera module derived from the inspection process are stored in the characteristic value storage unit provided in the camera module (S32). At this time, in addition to the characteristic value, information such as a date, a manufacturing line, and the like of the manufacturing process is stored as a characteristic value in the characteristic value storage section.

When the camera module is actually connected to the image signal processor and is operated after the characteristic value is recorded in the characteristic value storage unit, the image signal processor reads (S33) the characteristic values stored in the characteristic value storage unit , And initializes the video signal processor as the read characteristic value (S34).

In addition, when the video signal processor performs control of the camera module after the initialization, the video signal processor outputs information related to driving the camera module, for example, the total operation time of the camera module, Value storage unit.

As an example of the initialization of the image signal processor, an example of initialization using the values of the start code and the depth of field of the AF actuator will be briefly described below by comparing the conventional technique and the present invention.

(1) Example of use of start code of AF actuator

The start code of the AF actuator is a digital code representation of the point at which the actuator starts moving. It is normally used as 8 bits. Each module has a slightly different code that starts moving. Assuming that there are A camera module and B camera module that have undergone the production / inspection process in the manufacturing line, and that the start code value of the A camera module is 10 and the start code value of the B camera module is 20, The representative value of the two averages, 15, is defined as the start code of the corresponding camera model. When the video signal processor (ISP) drives the actuator unconditionally, the start is initialized to 15 and is controlled collectively. The value of 15 is a representative value made up of representative value / center value / deviation by securing several thousand or more data in the manufacturing process field. As a result, if A is controlled by a value of 15, it is already moving by "5", and B can not judge that the ISP has moved but has not yet moved.

On the other hand, according to the present invention, the AF actuator reads the Start Code stored in each characteristic value storing unit of the A camera module and the B camera module, and the value of A camera module is set to 10 and the value of B camera module is set to 20 Initialization can be an optimal control for the module.

(2) Depth of Field Example

The focal depth of the lens is a measure of the distance tolerance between the image sensor and the lens when the subject is correctly focused on the image sensor. If the depth is deeper, the tolerance range between the image sensor and the lens is so large that the AF actuator / algorithm can not accurately control the lens position even if the lens position is incorrect. However, if the depth is shallow, If you do not do it correctly, your focus will not be right.

Assuming that there are A camera module and B camera module that have undergone the production / inspection process in the manufacturing line and that the A camera module has a focus depth value of 10 [μm] and the B camera module is evaluated as 20 [μm] , B, and 15 [μm] are defined as the focal depth of this model, and control is performed within the tolerance range of 15 [μm] when controlling the lens position in the ISP. As a result, the A camera module is often out of focus, and the B camera module is always in focus.

On the other hand, according to the present invention, the focus depth value of the Depth of field stored in each characteristic value storage section of the A camera module and the B camera module is read, and the A camera module has a value of 10 according to each camera module, 20 is initialized to the optimal value for each camera module.

While the present invention has been described in connection with certain exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the patent of the present invention is not limited by the above-described embodiments, and it will be obvious that the patent scope covers not only the claims but also the equivalents.

1 is a block diagram showing a conventional camera image processing apparatus.

2 is a block diagram of a camera image processing apparatus according to an embodiment of the present invention.

3 is a flowchart illustrating a camera image processing initialization process according to an embodiment of the present invention.

Description of the Related Art [0002]

10: camera module 11: lens

12: image sensor 13: characteristic value storage unit

20: Video signal processor

Claims (13)

A camera image processing apparatus comprising a camera module and an image signal processor (ISP) for controlling the camera module, The camera module includes: lens; An image sensor for converting the optical image received through the lens into a video signal; A characteristic value storing unit for storing characteristic values indicating the performance of the lens and the image sensor, And, The characteristic value is derived from a tuning operation of the camera module, Wherein the image signal processor reads characteristic values stored in the characteristic value storage unit and performs initialization of the image signal processor and then controls the camera module. The camera image processing apparatus of claim 1, wherein the image signal processor writes or reads characteristic values of the characteristic value storage unit through a control bus connected between the camera module and the image signal processor. 2. The method of claim 1, wherein the characteristic value comprises at least one of Date, line (production date and production line), Depth of field, EPL (effective focus distance), BFL number, F number of camera, Max stroke, Start Code, Stroke of minimum step, Cut-off Frequency, , The resolution of the hot-pixel data of the image sensor, and the operation time (the total operating time of the camera module) of the lens, And a characteristic value indicating at least one of the characteristic values. delete delete delete delete delete The camera image processing apparatus according to claim 1, wherein the characteristic value storage unit is provided separately in the camera module. 10. The camera image processing apparatus of claim 9, wherein the characteristic value storage unit stores characteristic values of the image sensor. 11. The camera image processing apparatus according to claim 10, wherein the memory is an EEPROM or a flash memory or a rewritable memory. lens; An image sensor for converting a light image received through the lens into a video signal; A characteristic value storing unit for storing characteristic values indicating the performance of the lens and the image sensor, And, The characteristic value is derived from a tuning operation of the camera module, The characteristic values include production information of the corresponding camera module, lens information applied to the corresponding camera module, AF actuator information applied to the corresponding camera module, IR cut-off filter information applied to the corresponding camera module, image sensor information applied to the corresponding camera module, Wherein the camera module includes at least one of information of the camera module. 13. The method of claim 12, wherein the characteristic values include: Date and line (production date and production line), Depth of field, EPL (effective focus distance), BFL (distance between the image sensor and the last lens), F number, F number of camera, Max stroke, Start Code, Stroke of minimum step, Cut-off Frequency, , The resolution of the hot-pixel data of the image sensor, and the operation time (the total operating time of the camera module) of the lens, And at least one of the characteristic values indicating the characteristic values.

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