JP4510696B2 - Image processing apparatus and image processing method - Google Patents

Description

The present invention relates to an image processing apparatus and an image processing method , and more particularly to a technique suitable for use in encoding an image signal.

  Conventionally, the MPEG system is known as a technique for compressing the amount of information by encoding moving image data. The MPEG system is an encoding system that combines intra-frame encoding that encodes only image data in the same frame and inter-frame predictive encoding that encodes a difference (prediction error) from a reference frame.

  Prediction residuals in predictive coding and orthogonal transform coefficients in transform coding are considerably biased in the level distribution of generated signals. Therefore, if codes having different lengths are assigned in accordance with the occurrence frequency of the signal level, the average data amount can be shortened with respect to the fixed-length codes. The variable-length code is determined by a Huffman code or the like, and the total data amount is lowered as the data generation frequency is biased. As described above, when the variable-length code is used, the average data amount can be reduced as compared with the fixed-length encoding while maintaining the quality of the reproduction signal equal.

  However, when the above predictive encoding method is applied to image storage such as a digital TV or a digital video disc, the code amount differs depending on each picture, so that the transfer rate of image data (hereinafter referred to as data rate) is increased. How to control is a problem.

  The data rate control method is called group of picture (GOP), which controls the average number of bits in a predetermined section (usually more than a dozen frames) to keep the coding amount to be transferred constant. is there.

  That is, image data for one frame is divided into blocks called macroblocks having a predetermined number of pixels, and motion compensation prediction, orthogonal transformation, quantization, and the like are performed in units of macroblocks. The data rate after encoding of image data is controlled by controlling the average number of bits in the GOP to be almost constant by the quantization width used in the quantization at this time (Patent Literature). 1).

  In addition, when encoding, it is also considered to adjust the amount of code assigned to each block in the screen using an element called image complexity (activity) for each block. An activity is an element indicating the characteristics of an input image, and is devised to obtain a high-quality reproduced image corresponding to the characteristics of the image within a limited code amount.

JP-A-7-184195

  However, in the data rate control method, the activity is obtained without considering the number of bits allocated to the frame to be encoded, and is given as a disturbance to the reference quantization width obtained in consideration of the number of bits. When there are many macroblocks with small activity values, there is a problem that the amount of generated code exceeds the number of bits allocated to a frame.

  For example, in a recording apparatus that encodes moving image data by the MPEG method and records it on a disk medium or the like in real time, it is necessary to guarantee the recordable time of the recording medium within a certain error range. When the value fluctuates, there is a problem that the recordable time cannot be guaranteed.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to enable image encoding that guarantees a recording time set on a recording medium.

The image processing apparatus according to the present invention includes an input unit that inputs a moving image signal, an image complexity related to the moving image signal input by the input unit, and a remaining recording capacity of a recording medium that records the moving image signal. Variable generating means for generating a first variable based on the above, a quantization width setting means for setting a quantization width based on the first variable generated by the variable generating means, and a moving image input by the input means An orthogonal transform unit that orthogonally transforms an image signal to generate an orthogonal transform coefficient, and an orthogonal transform coefficient generated by the orthogonal transform unit are quantized with a quantization width set by the quantization width setting unit, and quantized Quantization means for generating coefficients, variable length encoding means for variable length encoding the quantized coefficients generated by the quantization means, and encoded moving image data output from the variable length encoding means Record Have a recording means for recording the body, said variable generating means, when the remaining recording capacity of the recording medium is smaller than a predetermined threshold value, fixing the value of the first variable to a predetermined value It is characterized by.
Another feature of the image processing apparatus according to the present invention is that an input unit that inputs a moving image signal, an encoding unit that encodes the moving image signal to generate encoded moving image data, and the code Complexity detecting means for detecting the complexity of the moving image related to the encoded moving image data generated by the encoding means, and the remaining recording capacity of the recording medium for recording the encoded moving image data encoded by the encoding means A first mode for controlling the encoding means based on complexity information detected by the complexity detection means, and a level of complexity detected by the complexity detection means. A second mode for controlling the encoding means without using information, and controlling the encoding means in the first mode or the second mode to output a code output from the encoding means Sign of video data And control means for recording the encoded moving image data whose code amount is adjusted by the control means on the recording medium, the control means based on the output of the remaining amount detection means Switching between the first mode and the second mode.

The image processing method of the present invention includes an input step for inputting a moving image signal, an image complexity related to the moving image signal input in the input step, and a recording remaining capacity of a recording medium for recording the moving image signal. A variable generation step for generating a first variable based on the first step, a quantization width setting step for setting a quantization width based on the first variable generated in the variable generation step, and a moving image input in the input step An orthogonal transformation step of orthogonally transforming an image signal to generate an orthogonal transformation coefficient, and an orthogonal transformation coefficient generated in the orthogonal transformation step are quantized with a quantization width set in the quantization width setting step, and quantized A quantization step for generating coefficients, a variable-length encoding step for variable-length encoding the quantization coefficient generated in the quantization step, and encoded video data output from the variable-length encoding step The have a recording step of recording on the recording medium, the variable generation step, when the remaining recording capacity of the recording medium is smaller than a predetermined threshold value, the value of the first variable to a predetermined value It is fixed .
According to another aspect of the image processing method of the present invention, an input step of inputting a moving image signal, an encoding step of encoding the moving image signal to generate encoded moving image data, and the code A complexity detecting step for detecting the complexity of the moving image related to the encoded moving image data generated in the encoding step, and a recording remaining capacity of the recording medium for recording the encoded moving image data encoded in the encoding step A first mode for controlling the encoding operation of the encoding step based on the complexity information detected in the complexity detection step, and a detection in the complexity detection step. A second mode for controlling the encoding operation of the encoding step without using complexity information, and controlling the encoding step in the first mode or the second mode, In the encoding process A control step of adjusting the code amount of the encoded moving image data to be output; and a recording step of recording the encoded moving image data adjusted in the code amount in the control step on the recording medium, the control step Is characterized in that the first mode and the second mode are switched based on the output of the remaining amount detection step.

According to the present invention, the remaining amount of the recording medium is monitored, and when the remaining recording capacity of the recording medium becomes smaller than a predetermined threshold, the value of the first variable for setting the quantization width is set to a predetermined value. since so as to fix the, when the capacity of the recording medium is running low, the effects of the activity, given as a disturbance in the reference quantization step size can be or adaptively reduce or, or disabled. As a result, when there are many macroblocks with small activity values, the number of bits allocated to the frame is exceeded, and the problem that the recording time required for the recording medium cannot be guaranteed can be solved.

(First embodiment)
Hereinafter, a preferred embodiment of an image encoding apparatus according to the present invention will be described in detail with reference to FIG.
FIG. 1 is a block diagram of an image encoding apparatus according to the present invention. As shown in FIG. 1, the image coding apparatus according to the present invention includes a block division unit 1, a motion compensation unit 2, an orthogonal transformation unit 3, a quantization unit 4, a variable length coding unit 5, a recording unit 5a, and a bit allocation unit. 6, a reference quantization width determination unit 7, an activity calculation unit 8, a multiplication unit 9, an average value calculation unit 10, and an activity control unit 11.

  The block dividing unit 1 divides the input original image data into macroblocks having a predetermined number of pixels (16 × 16 pixels), and the image data of the macroblock (hereinafter referred to as MB data) is the motion compensation. Output to the unit 2 and output to the activity calculation unit 8.

  The motion compensation unit 2 includes a dequantization unit, an inverse orthogonal transform unit, a motion compensation unit, and the like (not shown), and a prediction error between the current MB data input from the block division unit 1 and the reference image data. Is output to the orthogonal transform unit 3. That is, in the motion compensation unit 2, the previous quantized MB data obtained by the quantization unit 4 is inversely quantized by an inverse quantization unit, and inverse orthogonal transform is performed by an inverse orthogonal transform unit, The restoration value (restored image data) of the previous MB data is obtained. This restored image data is used as reference image data for inter-frame prediction in the motion compensation unit 2.

  Next, the orthogonal transform unit 3 transforms the prediction error data into data suitable for encoding (hereinafter referred to as transform coefficients) by two-dimensional orthogonal transform such as DCT (discrete cosine transform). Then, the transform coefficient is output to the quantization unit 4.

  The quantization unit 4 quantizes the input transform coefficient with a quantization width obtained from a multiplication unit 9 described later. The number of values that the transform coefficient can take (hereinafter referred to as the number of levels) is controlled by this quantization width. That is, if the quantization width is large, the number of levels decreases, thereby increasing the number of zeros and reducing the significant coefficient other than zero. Therefore, the amount of encoded data after Huffman encoding in the variable length encoding unit 5 is also reduced. Also, if the quantization width is small, the number of 0s decreases and the significant coefficient increases, so that the amount of encoded data after Huffman encoding in the variable length encoding unit 5 also increases.

  That is, since the amount of encoded data can be controlled by controlling the quantization width, the data transfer rate after encoding by the variable length encoding unit 5 (hereinafter referred to as the data rate) is controlled. Can do. Then, the transform coefficient quantized by the quantization unit 4 is output to the variable length encoding unit 5 and also to the motion compensation unit 2.

The variable length coding unit 5 performs variable length coding (Huffman coding) on the transform coefficient quantized by the quantization unit 4. The encoded transform coefficient (hereinafter referred to as encoded data) is output to a buffer memory (not shown), and the recording unit 5a reads out from the buffer memory at a constant data rate and records it on the recording medium 12. Further, the coded data is variable transferred to the bit allocation unit 6 to be described later from the variable-length coding unit 5.

  The activity control unit 11 detects the recording capacity (remaining area of the recordable area) w of the recording medium 12 and the recording time t up to now. The activity control unit 11 controls the activity calculated by the activity calculation unit 8 step by step using the recording capacity w and a plurality of preset threshold values. In the present embodiment, a case where there are two threshold values, Th1 and Th2 (where Th1> Th2), will be described as an example.

Here, each of the threshold values Th1, Th2 (where Th1> Th2) is determined using a predetermined reference value W _TH1 , W _TH2 (where W _TH1 , W _TH2 ) and a recording time t,
TH1 = W _TH1 × t and TH2 = W _TH2 × t.
When the following relationship holds between the recording capacity w and the threshold values Th1 and Th2 (where Th1> Th2):

In the case of (i), it is determined that the recording capacity of the recording medium is small, and the second activity control flag flg2 is turned on and output to the activity calculation unit 8. When this condition is not satisfied, flg2 is turned off.

In the case of (ii), it is determined that the recording capacity of the recording medium has been reduced, and the first activity control flag flg1 is turned on and output to the activity calculation unit 8. When this condition is not satisfied, flg1 is turned off.

In the case of (iii), it is determined that the recording capacity of the recording medium has a sufficient margin, and nothing is output to the activity calculation unit 8 in particular. In this embodiment, the number of thresholds is set to two. However, by further increasing the number of thresholds, the determination of the remaining storage capacity of the recording medium can be further changed stepwise.

The activity calculation unit 8 obtains an activity for each macroblock, and the activity act _j of the _jth macroblock is obtained by the following equation (Equation 2).

Here, var _i , _j is a dispersion value of the pixel value of the i-th sub-block when the j-th macro block is divided into four blocks. That is, if the macroblock is composed of 16 pixels × 16 pixels, the sub-block is 8 pixels × 8 pixels, the number of pixels is 64, and the variance value is obtained for these 64 pixels.

The activity calculation performed in the activity calculation unit 8 may use a dynamic range of pixel values instead of a variance value of pixel values. The activity obtained in this way is converted into an activity Nact _j normalized by the average value of the quantization width obtained by the average value calculation unit 10 as in the following equation (Equation 3).

Here, avg is an average value of the quantization width obtained by the average value calculation unit 10, and m is an arbitrary natural number. However, as the average value avg, a predetermined initial value is set at the initial stage of encoding. The normalized activity Nact _j is output to the multiplication unit 9 together with a reference quantization width output from a reference quantization width determination unit 7 described later.

  The activity is calculated by the variance of the pixel values of the macroblock. For example, when a flat portion is included in a macroblock, the activity of the macroblock is reduced, and when an edge is included in the flat portion, the activity is increased. Further, when the activity is output to the multiplication unit 9, the activity is normalized and output based on the average value of the quantization width of the previous frame output from the average value calculation unit 10. Then, the multiplication unit 9 corrects the reference quantization width obtained by the reference quantization width determination unit 7 with the normalized activity to determine the quantization width.

  However, when any of the activity control flags output from the activity control unit 11 is ON, the activity calculation result is changed depending on which flag is set.

In the present embodiment, a case will be described in which the activity control unit 11 has two thresholds using the first activity control flag flg1 and the second activity control flag flg2. Nact _j when the first activity control flag flg1 or second activity control flag flg2 is ON is changed to Nact' _j by the following equation (Equation 4), is output to the multiplier 9.

Here, dec is a constant satisfying 0.1 ≦ dec ≦ 1.0.
First, when the second activity control flag flg2 is ON, it is determined that the recording capacity of the recording medium is small, and when Nact _j is smaller than 1.0 in order to eliminate disturbance to the data rate control due to the activity, 1.0 Is output to the multiplication unit 9. However, when Nact _j is 1.0 or more, it is output as it is. Alternatively, 1.0 may always be output without calculating Nact _j .

On the other hand, when the first activity control flag flg1 is ON, it is determined that the recording capacity of the recording medium 12 has decreased, and the normalized activity is reduced in order to reduce the influence of disturbance on the data rate control due to the activity. Nact _j is the case less than 1.0 outputs a Nact' _j plus the correction value dec to the multiplier 9.

  In the present embodiment, the number of thresholds is set to two. However, it is possible to further increase the number of thresholds and change the remaining storage capacity of the recording medium in a stepwise manner. In that case, it is sufficient to change dec step by step according to the remaining amount of the recording medium.

The multiplication unit 9 corrects the reference quantization width by multiplying it by the normalized activity Nact _j to determine the quantization width. The quantization width is output to the quantization unit 4 and is also output to the average value calculation unit 10.

  The average value calculation unit 10 calculates the average value of the quantization width for one frame, and outputs this quantization width to the bit allocation unit 6 and also to the activity calculation unit 8.

  In addition, the bit allocation unit 6 will perform encoding based on the encoded data such as the number of generated bits up to the previous frame by the variable length encoding unit 5 and the data rate given to the variable length encoding unit 5. The number of bits to be assigned to the frame being determined is determined.

The reference quantization width determination unit 7 sets the reference quantization widths q ^I _j , q ^P _j , and q ^B _j for each macro block based on the number of generated bits up to the previous macro block and the allocated number of bits. decide. Here, j represents a macroblock number, and I, P, and B represent picture types. For example, the buffer fullness d ^I _j in the jth block of the I picture is obtained by the following equation (Equation 5).

Based on d ^I _j obtained by the above equation 3, the reference quantization width q ^I _j is obtained by the following equation (Equation 6).

Here, d ^I ₀ is the initial buffer fullness, and is the last buffer _fullness d ^I _MBcnt when the previous I picture was encoded. However, the initial value is an arbitrary constant. B _j is the total number of bits generated in the image up to the j-th block, MB _cnt is the total number of macroblocks in the image, and r is a reaction parameter. When the above equation 5 allocated equally is T _i bits in each macroblock, a difference between the actual number of generated bits and the allocation bit number to generate up to the previous macroblock, are reflected in the virtual buffer fullness .

  Therefore, according to the above formulas 5 and 6, if the number of bits generated in the previous macroblock is large, the virtual buffer fullness is increased, thereby increasing the reference quantization width. As a result, the reference quantization width determination unit 7 works to reduce the number of bits generated in subsequent frames.

  On the other hand, when the number of bits generated in the previous macroblock is small, the virtual buffer fullness is reduced, and thereby the reference quantization width is reduced. As a result, the reference quantization width determination unit 7 works to increase the number of generated bits in subsequent frames. Note that the reference quantization width is determined using the same method for the P picture and the B picture.

Next, the schematic operation of the image processing apparatus of the present embodiment configured as described above will be described with reference to the flowchart of FIG.
As shown in FIG. 3, when the process is started, it is determined in the first step S41 whether or not a moving image signal has been input. If a moving image signal is input as a result of this determination, the process proceeds to step S42, and the first based on the complexity of the image related to the input moving image signal and the remaining recording capacity of the recording medium on which the moving image signal is recorded. Generate variables for.

  Next, it progresses to step S43 and sets a quantization width | variety based on the 1st variable produced | generated in step S42. In step S44, the input moving image signal is orthogonally transformed to generate an orthogonal transformation coefficient obtained by transforming the macroblock image data.

  In step S45, the orthogonal transform coefficient generated in step S44 is quantized with the quantization width set in step S43 to generate a quantized coefficient. Next, the process proceeds to step S46, and the quantization coefficient generated in step S45 is variable-length encoded.

  Next, the process proceeds to step S47, and the encoded moving image data subjected to variable length encoding in step S46 is recorded on the recording medium 12. Thereafter, in step S48, it is determined whether or not all image processing has been completed. If processing remains, the process returns to step S42 to repeat the above-described processing. If the result of determination in step S48 is that there is no process left, the process ends.

  As described above, according to the image encoding device of the present embodiment, the first encoding is based on the complexity of the image related to the input moving image signal and the remaining recording capacity of the recording medium that records the moving image signal. Since the quantization width is set based on the generated first variable, the influence of the activity given as a disturbance to the data rate control is invalidated when the capacity of the recording medium 12 is reduced. Or the direction of further reducing the amount of generated code. As a result, the data rate control can be performed reliably, and the recording time required for the recording medium can be guaranteed.

(Second Embodiment)
Next, another embodiment of the image coding apparatus according to the present invention will be described in detail with reference to FIG. However, the image coding apparatus according to the second embodiment has substantially the same structure as that of the first embodiment, but has an input unit 53 and an activity control method of the activity control unit 51.

  First, the block division unit 41, the motion compensation unit 42, the orthogonal transformation unit 43, the quantization unit 44, the variable length coding unit 45, and the recording unit 45a perform the same operations, and thus the description thereof is omitted. The activity control unit 51 detects the recording capacity (remaining area of the recordable area) w of the recording medium 52 and the recording time t up to now. Further, the activity control unit 51 simultaneously detects a recording mode mode corresponding to the moving image quality set by the user from the input unit 53. The activity control unit 51 sets a plurality of thresholds according to the recording mode mode and the recording capacity w, and controls the activity step by step.

In this embodiment, as the recording mode mode,
High image quality mode = high
Standard recording mode mode = mid
Low quality mode mode = low
A case where there are three types of modes will be described.

First, predetermined reference values w _high , w _mid , w _low set in each mode are set so that w _high > w _mid > w _low, and thresholds are set to Th _high = w _high × t, TH _mid = _Let w _mid × t and Th _low = w _low × t. This is because the recording mode mode represents the image quality, that is, the average bit rate. For example, when mode = high, the average bit rate increases compared to mode = mid and mode = low, and the capacity of the recording medium decreases sooner. Therefore, the threshold value is set to be larger than in other modes. is there.

  In this way, after setting a reference threshold value in accordance with the recording mode mode, the case of Equation 1 in the first embodiment is performed. Assuming that each mode has two threshold values as in the first embodiment, in the present embodiment, the equation corresponding to the above equation 1 is obtained as the following equation.

Since there are three recording mode modes, there are six flags: flg _low 1, flg _low 2, flg _mid 1, flg _mid 2, flg _high 1, flg _high 2. A method similar to that of the first embodiment may be performed separately and is omitted. The subsequent activity calculation unit 48, average value calculation unit 50, multiplication unit 49, bit allocation unit 46, and reference quantization width determination unit 47 perform the same operations, and thus detailed description thereof is omitted.

  In the present embodiment, three modes are set as the recording mode mode. However, the number of modes may be increased, and activity control corresponding to the image quality may be performed stepwise. Conversely, the number of modes may be reduced to reduce the number of stages of activity control corresponding to the image quality.

The schematic operation of the image processing apparatus according to the second embodiment will be described below with reference to the flowchart of FIG.
As shown in FIG. 4, when the process is started, it is determined in step S51 whether or not a moving image signal has been input. If a moving image signal is input as a result of this determination, the process proceeds to step S52, and the moving image signal input in step S51 is encoded to generate encoded moving image data. Next, proceeding to step S53, the complexity of the moving image related to the encoded moving image data generated at step S52 is detected.

  Next, proceeding to step S54, the remaining recording capacity of the recording medium 52 on which the encoded moving image data encoded at step S52 is recorded is detected. In step S54, a recording mode mode corresponding to the moving image quality set by the user input from the input unit 53 is simultaneously detected.

  Next, the process proceeds to step S55, and it is determined whether or not the remaining recording capacity detected in step S54 is greater than a predetermined remaining capacity. As a result of the determination, if the remaining recording amount is larger than the predetermined remaining amount, the process proceeds to step S56, and if smaller, the process proceeds to step S57.

  In step S56, encoding is executed in the first mode. In the first mode of the present embodiment, the activity is controlled according to the complexity information calculated in step S53, the recording mode mode set by the user, and the recording capacity w of the recording medium 52, and an encoding operation is performed. To control.

  On the other hand, in step S57, encoding is performed in the second mode. In the second mode of the present embodiment, the encoding operation in the encoding step is controlled without using the complexity information calculated in step S53.

  Next, the process proceeds to step S58, and a process of recording the moving image data encoded in step S56 or step S57 on the recording medium 52 is performed. Thereafter, in step S59, it is determined whether or not all image processing has been completed. If processing remains, the processing returns to step S52 and the above-described processing is repeated. If the result of determination in step S59 is that no processing remains, the processing ends.

  According to the present embodiment, since the operation mode is switched according to the remaining recording capacity of the recording medium 52, recording is performed in the recording mode mode set by the user, and when the recording capacity of the recording medium 52 decreases. The recording method can be switched, and activity control according to the image quality can be performed.

(Another embodiment according to the present invention)
Each means constituting the image processing apparatus and each step of the image processing method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable recording medium recording the program are included in the present invention.

  Further, the present invention can be implemented as, for example, a system, apparatus, method, program, or recording medium, and can be applied to a system composed of a plurality of devices. Moreover, you may apply to the apparatus which consists of one apparatus.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowcharts shown in FIGS. 3 and 4) for realizing the functions of the above-described embodiments is directly or remotely supplied to a system or apparatus. In addition, it includes the case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of an object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, the present invention includes a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer.

  In addition, the program of the present invention is encrypted, stored on a recording medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instructions of the program is used for the actual processing. The functions of the above-described embodiment can be realized by performing some or all of the processes.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows the schematic structure of the image coding apparatus in the 1st Embodiment of this invention. It is a block diagram which shows the structure of the outline of the image coding apparatus in the 2nd Embodiment of this invention. It is a flowchart explaining the 1st operation example of the image processing method of this invention. It is a flowchart explaining the 2nd operation example of the image processing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Block division part 2 Motion compensation part 3 Orthogonal transformation part 4 Quantization part 5 Variable length encoding part 5a Recording part 6 Bit allocation part 7 Reference quantization width determination part 8 Activity calculation part 9 Multiplication part 10 Average value calculation part 11 Activity Control unit 12 Recording medium 41 Block division unit 42 Motion compensation unit 43 Orthogonal transformation unit 44 Quantization unit 45 Variable length encoding unit 45a Recording unit 46 Bit allocation unit 47 Reference quantization width determination unit 48 Activity calculation unit 49 Multiplication unit 50 Average Value calculation unit 51 Activity control unit 52 Recording medium 53 Input unit

Claims (7)

An input means for inputting a moving image signal;
Variable generating means for generating a first variable based on the complexity of the image related to the moving image signal input by the input means and the remaining recording capacity of the recording medium for recording the moving image signal;
Quantization width setting means for setting a quantization width based on the first variable generated by the variable generation means;
Orthogonal transformation means for orthogonally transforming the moving image signal input by the input means to generate an orthogonal transformation coefficient;
Quantizing means for quantizing the orthogonal transform coefficient generated by the orthogonal transform means with a quantization width set by the quantization width setting means, and generating a quantization coefficient;
Variable-length coding means for variable-length coding the quantization coefficient generated by the quantization means;
The encoded moving image data output from said variable length coding means have a recording means for recording on the recording medium,
The image processing apparatus , wherein the variable generation means fixes the value of the first variable to a predetermined value when a remaining recording capacity of the recording medium becomes smaller than a predetermined threshold value. .   The variable generation unit further generates a second variable according to a difference between a code amount of the encoded moving image data output from the variable length encoding unit and a target code amount, and the quantization width setting unit includes The image processing apparatus according to claim 1, wherein the quantization width is set based on the first variable and the second variable.   The variable generation means fixes the value of the first variable to a predetermined value when the remaining recording capacity of the recording medium becomes smaller than a predetermined threshold, and performs the quantization only by the second variable. The image processing apparatus according to claim 2, wherein a width is set. An input means for inputting a moving image signal;
Encoding means for generating encoded moving image data by encoding the moving image signal;
Complexity detecting means for detecting the complexity of the moving image related to the encoded moving image data generated by the encoding means;
A remaining amount detecting means for detecting a remaining recording capacity of a recording medium for recording the encoded moving image data encoded by the encoding means;
A first mode for controlling the encoding means based on the complexity information detected by the complexity detection means; and the encoding means without using the complexity information detected by the complexity detection means And controlling the encoding means in the first mode or the second mode to adjust the code amount of the encoded moving image data output from the encoding means Control means to
Recording means for recording the encoded moving image data, the code amount of which has been adjusted by the control means, on the recording medium,
The image processing apparatus characterized in that the control means switches between the first mode and the second mode based on the output of the remaining amount detection means. The control means selects the first mode when the remaining recording capacity of the recording medium is larger than a predetermined threshold, and selects the second mode when the remaining capacity is smaller than the predetermined threshold. The image processing apparatus according to claim 4 . An input process for inputting a moving image signal;
A variable generating step for generating a first variable based on the complexity of the image related to the moving image signal input in the input step and the remaining recording capacity of the recording medium for recording the moving image signal;
A quantization width setting step for setting a quantization width based on the first variable generated in the variable generation step;
An orthogonal transform step of orthogonally transforming the moving image signal input in the input step to generate an orthogonal transform coefficient;
A quantization step of quantizing the orthogonal transformation coefficient generated in the orthogonal transformation step with the quantization width set in the quantization width setting step, and generating a quantization coefficient;
A variable-length encoding step for variable-length encoding the quantization coefficient generated in the quantization step;
The encoded moving image data output from the variable length coding process have a recording step of recording on the recording medium,
The image processing method characterized in that the variable generation step fixes the value of the first variable to a predetermined value when a remaining recording capacity of the recording medium becomes smaller than a predetermined threshold value. . An input process for inputting a moving image signal;
An encoding step of encoding the moving image signal to generate encoded moving image data;
A complexity detection step of detecting the complexity of the moving image related to the encoded moving image data generated in the encoding step;
A remaining amount detecting step for detecting a remaining recording capacity of a recording medium for recording the encoded moving image data encoded in the encoding step;
The first mode for controlling the encoding operation of the encoding step based on the complexity information detected in the complexity detection step, and without using the complexity information detected in the complexity detection step A second mode for controlling the encoding operation of the encoding step, and controlling the encoding step in the first mode or the second mode to output in the encoding step A control step of adjusting the code amount of the moving image data;
A recording step of recording the encoded moving image data whose code amount is adjusted in the control step on the recording medium,
In the control step, the first mode and the second mode are switched based on an output of the remaining amount detection step.

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