TWI221742B - Quantization matrix adjusting method for quality improvement - Google Patents

Abstract

A quantization matrix adjusting method for quality improvement by scaling down the default quantization matrix. The adjusting method comprising the steps of: updating a used bits BB_X and an average quantizer scale Avg_Q; allocating the bit budget BB_C for the current picture; calculating an estimated quantizer scale Est_Q according to the used bits BB_X, average quantizer scale Avg_Q and the bit budget BB_C; deciding the operation mode, the encoder entering an adjusting mode when the estimated quantizer scale Est_Q is smaller than a threshold Th_Q, otherwise the encoder remaining at normal mode; scaling down the default quantization matrix as a new quantization matrix when the operation mode is the adjusting mode; and coding the current picture, the encoder coding the current picture using the new quantization matrix and default quantization matrix in the adjusting mode and normal mode, respectively.

Description

1221742 No. 1 92112855 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a quantization matrix adjustment method for improving image quality, and particularly to a quantization matrix adjustment method for reducing image quality by using a reduced quantization matrix. 2. [Previous Technology] In order to reduce the amount of image data, the image is generally compressed, such as MPEG-based image coding (coding). The basic unit of image coding is a macro-block. If the sampling is 4: 2: 0 format, then each macro block has 6 blocks, which are 4 Y blocks, one cb block, and one Cr block. The parent blocks must first undergo a discrete cosine transform (d i s c r e 丨 e c 〇 s in e transform, hereinafter referred to as DCT), and then the DCT coefficients (coefficient) are quantized into integers. A zigzag scan or other alternative scanning method is used to arrange a two-dimensional (tw〇1 dimension) quantization coefficient array into one-dimensional (menu-dimensi) data. Finally, the so-called variable-length coding (hereinafter referred to as VLC) is used for entropy coding. In general, the quantization of the DCT coefficients F [v] [u] can be expressed as: QF [v] [u] = 16 * F [v] [u] / (Q * w [v] [u]) ... (1) Among them, v, U are indexes of the two-dimensional array, ranging from 0 to 7. Q is the quantizer scale of each block in each macro block, which can be changed with different macro blocks. W [v] [u] is the quantization matrix defined by the entire picture, which is used to specify the weight of each different DCT coefficient

1221742 _ case number 92112855_ year month day ____ 5. Description of the invention (2) Weighting factor. Figure 1 shows the preset quantization matrix defined for the intra block in the MPEG-2 specification. As shown in the quantization matrix of Fig. 1, the value of the quantization matrix gradually increases as the array indices v, u increase. This characteristic makes quantization coefficients with high frequencies easier to become 0, because human eyes are more sensitive to low-frequency signals and less sensitive to high-frequency signals. In addition, inverse-quantization is used to recover DCT coefficients. The inverse quantization of the commonly quantized DCT coefficients QF [v] [u] is defined as:

F ’[v] [u] = QF [v] [u] * Q * W [v] [u] / 16… (2) where F’ [v] [u] is the DCT coefficient of the reply. The difference between the original DCT coefficient F [v] [u] and the returned DCT coefficient F '[v] [u] is called the quantization error and is defined as: E [v] [u] = F [v] [u]-F '[v] [u]… (3)

The quantization scale factor Q is used to adjust the content of the quantization matrix w [v] [u]. The Q value ranges from 1 to 31. The adaptive quantization applied to MPEG-1 and MPEG-2 can randomly change the Q value of each macro block, but in MPEG-4, it can only slightly adjust adjacent macro blocks. Q value. Furthermore, MPEG-2 has an actual quantization scale factor that corresponds to a non-linearity from (1 to 3 1) to (0 · 5 to 5 6). Adjusting the quantization scale factor Q can control the bit consumption and coded quality of the macro block. For a larger Q value, the quantized DCT coefficient becomes smaller, resulting in more quantization]) The ct coefficient is 0. Therefore, the coded bit stream (c〇d ed b i t

Page 8 1221742 Case No. 92112855 Fifth, the description of the invention (3) stream) will become shorter. However, as a result, the quantization error becomes larger, resulting in poorer image quality after decoding. If we want to get better image quality, we must set a smaller Q value to reduce the quantization error, but the encoding bit stream will become longer. In general applications, the bit rate (bit-rate) of the MPEG bit stream is limited (con s t ra i ne d). For example, in the Digital Versatile Disk (DVD) standard, it is defined that the bit rate of the mpeg-2 video stream (video stream) cannot be higher than 98Mb per second, so the bit consumption must be controlled during the encoding process to meet This restriction.

The content of each image in a series of video diurnal changes, and the complexity of the encoding (complexi ty) varies from part to part. The video buffer verifier (hereinafter referred to as VBV) used in MPEG-1 provides the bit rate consumption flexibility (f lexibi 1 ity) for different images, but the overall bit rate for a long time is still Is a constant bit rate (constant bit rate, hereinafter referred to as CBR). And MPEG-2 introduced

The variable bit rate (VBR) operation mode 'provides greater flexibility in the variation of the bit rate consumption of each image. v The BV buffer is used to emulate the input buffer of the MPEG decoder, and the bit stream generated by the MPEG encoder must not violate the restrictions of the vBV buffer, otherwise the bit stream cannot be decoded properly . Figure 2 shows a schematic diagram of the V B V buffer in c B R interpolation mode. As shown in the figure, the oblique line portion represents the encoded data input to the buffer at a fixed bit rate, and the vertical line portion represents the data of the decoded image that is momentarily removed from the buffer. In order to make the bit stream meet the requirements of MPEG bit control, when the calculus horse implement needs to solve the calculus horse, you need ΛΑ times, 丨 ,, 丨 ,, 1 M wu _.

Page 9 1221742 V. Description of the invention (4) The buffer of the encoder must not be overfilled. Referring to FIG. 2, if an image consumes too many bits, the VBV buffer may be underflowed. Therefore, the upper bound of allocable Mts is UB. Similarly, if an image consumes too few bits, the VBV buffer may overflow the data (〇ver |: i〇w), so bit one (311〇03 饨 13 16 1) can be allocated " 3) The lower limit (1〇 ^ 1 * 1) 01111 (1) is 1 ^. Figure 3 shows the schematic diagram of VBV buffer in VBR operation mode. The difference between VBR and CBR operation modes is that VBR operation mode is specified The maximum bit rate is input to the VBV buffer until the VBV buffer is fully loaded, so the average bit rate input rate of the VBR operating mode is variable. Therefore, VBR has no minimum bit limit. Limitation. In order to meet the limitation of VBV, the editor must assign one image to each image, and then try to control the actual consumption bit buff. The virtual buffer mechanism (virtual buiier mechamsm) is generally used. To control the bit consumption. At 0, the quantization scale factor Q is set to ^ Erli-Ancient private day kw τ should be 1 and when the buffer occupies 2; a threshold R (threshold), then The quantization ratio is 31. The threshold R is generally called the response factor Before the code, virtual buffer ctor). The initial quantization scale factor Q is two :: The device uses this quantization scale factor ㈣ q / 3 ": to combine and edit i — a giant #block elimination set ^^ into the budget If the value is', the virtual buffer occupancy is increased by two miles: · The amount D greater than the average bit is reduced. If there is a virtual buffer in the virtual buffer, the _status thinker bit page 1212742

In order to reduce the bit / shaw consumption rate, the quantization scale factor Q is increased. The right virtual buffer occupancy 1) is reduced below 40-R / 3i, and the quantization scale factor QΛ ^ will 卞 4 β into qO-1 again. This condition means that the bit consumption is lower than the expected value 'to reduce the quantization scale factor Q in an attempt to increase the position of the virtual gain per unit. If you ask again, the range of the video will change even if it is caused by the rate. The question of how to use the virtual and buffering mechanism to control bit consumption is how to refer to the initial buffer occupancy d0. The initial buffer occupation amount do is an estimated value of the coding complexity of the current picture. Regarding the fixed π budget value, if the complexity of the current image is relatively high, it is necessary to select a relatively large initial buffer occupancy d 0, and the quantization scale factor Q of the block is relatively increased. However, editor 2: The complexity of the current image until the image is actually encoded. , T-type inheritance (inherit) the virtual ease of the previous image ::: kind: a single method can handle most situations without causing insufficient VBV data. When W 支 is changed, the range of the quantization scale factor Q for each set of blocks is from [correction: "most of the state of video coding. However, when a series of 2 non-ΐ target bit rates are high, 'quantization' Scale factor reserve: 'The scale is early. More bits. # To when the video is really too simple: the dimorphization ratio is set to 丨 both can not be produced, you need to increase the stuffing bits, and the bit compliance ratio When the factor “Av” is 丨 · 5, for most

Then, or ^ =: =: is 15, but it must be-the smaller the value of the scale factor becomes, the smaller the solution is 1221742 1? Tiger 92112855 V. Description of the invention (6) The coarser the resolution becomes (coarser ), Resulting in a quantitative change between 1 and 2, making the image flat and smooth "/ Qian Shaoyan block effect (b1ocking artifact). The domain is slightly visible. [Summary of the invention] is to provide a quantized matrix image quality that can avoid quantitative image quality. The adjustment mode is set to the general modulation matrix, the average quantization ratio, and the quantization ratio, and the bit to adjust the modulo value. When the adjustment quantization matrix is adjusted according to the reduction, the quantization matrix of the root is reduced, which can increase the encoded video product Depending on the block effect. In view of the above problems, the objective scale factor resolution of the present invention becomes coarse, and an adjustment method can be provided at the same time. In order to achieve the above object, the method for improving shading of the present invention includes the following steps: updating the used factor; and assigning a bit budget value factor to the current image, which is calculated based on the used bit amount and the average amount of the budget value. Scale factor; judgment formula, when the estimated scale factor is less than one quantization, the coding mode is set to the adjustment mode, 'otherwise the transformation matrix is preserved, when the coding mode is the adjustment mode, the scaling is reduced; and when the coding mode is small, After that, the quantity = matrix is used for encoding. When the encoding module is encoded according to a preset quantization matrix. Because the invention presets the adjustment measurement mode to avoid the measurement scale factor being too low, the quality and avoid the generation of flat image area;

Array adjustment method. y When the calculated estimated scaling factor EstQ — C of the current image is changed to be small, and the current image is encoded with a preset quantization matrix, the flat shadow area will produce a slightly visible block effect. In order to solve this problem, the encoder of this and Ming uses the weight (quantity reduction) of the quantization matrix to reduce the estimated scaling factor EstQ_C to a larger value by ^. For example, as shown in formula (^), when the preset quantization matrix W [v] [u] is reduced to 1/4, the average quantization scale factor Avg_Q can be enlarged from 丨 .5 to 6, at this time the quantization scale factor Q can be increased to 7 or 8 to reduce bit rate consumption, or 5 or 4 to increase bit rate consumption. Therefore, the quantization error of adjacent macroblocks can be greatly reduced. / In the MPEG-1 and MPEG-2 specifications, a sequence of header information must be placed at the beginning of each encoded bitstream, and this header can be added to subsequent bitstreams. Once the decoder receives the header data, the quantization matrix W [v] [u] is set to the default value. In MPEG — A, a customized quantization matrix W [v] [u] can only be set in the header, and the header can only be inserted into a group of images (Group 〇 ctures, hereinafter referred to as GOP). This means that when the decoder wants to change the quantization matrix, the decoder must restart a G0P, insert a header data before G0P, and configure a new quantization matrix in the header data. In MPEG-2, the new quantization matrix can not only be placed in the header data, but also an epitaxial quantization matrix can be inserted. Therefore, if the decoder wants to change the quantization matrix, it must be before each picture is encoded.

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Case No. 921128! ^ V. Description of the invention (8) The image is analyzed in advance to perform the encoding operation of the current image. The complexity of the image is analyzed by scanning in advance, that is, the image is edited, flattened, and it is unknown that the TEST model 5 (teSt model 5, TM5) bit rate control exercise is like rate control a 1 g〇ri thm), the encoder can only use the nose image to estimate the complexity of the current image. In the first embodiment: two encoding steps: Steps are as follows: Step S40 2: Update the used bit quantity BB-χ and the pingdan factor Avg-Q. After an X image (X can be]; image, ρ image, or β = encoding, the encoder obtains the average quantized image of the X image.

Avg_Q 'Finally the virtual buffer occupancy is 乜 乂, and the factor BB —X is known. Use a bit amount Step S4 0 4 ·· Specify a bit budget value ββ for the current image. . In all cases, the initial virtual buffer occupancy of the next image is already set as the final virtual buffer occupancy d_X, and the initial quantization ratio ^ is set to be the average quantization scale factor AVg-Q. Furthermore, the budget value BB-C for the 4th bit is specified by the frame-level rate control. "Eye position of the image step S40 6: Calculate the estimated scale factor" by ^. Adjacent images of a format have roughly the same degree of activity, so because of the same used bit amount BB-X for one image, BB-C for the current image, and average quantization scale factor A q To calculate the measured ratio of 70 budget values due to his tQ_c: — like the estimate

EstQ-C = (BB-X / BB-C) * Avg-Q. (4) Step S40 8: Detect whether to enter the adjustment mode. When the estimation factor EstQ — C is less than a threshold of the scale factor ThQ X, you will reduce the ratio _ two. For example, ThQ-X is page 14 1221742

s, 3, or 4 indicates that the image content of the video is 疋 for the given bit rate, when it is pure. If the used bit amount BB_X of the previous encoded image and the bit budget value BB__C assigned to the current image are approximately equal, it can be guessed that the bit budget value BB — C assigned to the current image will cause an estimation Quantization scale * The factor Es tQ-C is too small. Therefore, when the estimated scale factor EstQ —c is smaller than and the scale factor is gated, the encoder enters the adjustment mode of step S4 10, otherwise it is processed in the general mode of step S416. ^ Step S41 0. The reduced quantization matrix becomes a new quantization matrix. In the adjustment mode ^, the encoder will hope to increase the final average quantization scale factor of the current image to a safe value SQ —X, and the safety value SQ —χ may be greater than or equal to the threshold of the scale factor ThQ_x. Therefore, the present invention will use an adjustment factor S to reduce the preset quantization matrix, and the initial virtual buffer occupancy will be increased to d0-x / s. The adjustment factor s is a value less than 1, and can be calculated by the following formula: S = EstQ-C / SQ-X… (5) and the new quantization matrix W, [v] [u] is: W '[v] [u] = W0 [v] [u] * s (6) where v and 11 are indices from 0 to 7. W0 [v] [u] can be a preset quantization matrix or a user-defined quantization matrix. Therefore, the larger the safety value is, the smaller the adjustment factor S is. For example, the safety value SQ —χ is 6. Since the minimum value of the quantization matrix is 1, the minimum value of the contents of W, [v] [u] is limited to j. In addition, two quantization matrices are used in the encoder, one for intra blocks and the other for inter blocks. Because updating a quantization matrix requires 5 丨 2 bits to encode the quantization matrix itself and some additional bits,

Page 15 1221742 Case number 92112855

V. Description of the invention Under (10), the number of quantization matrix updates can be minimized. For example, the internal quantization matrix is needed, and the B image is only necessary to update the correlation t. For P-pictures, there is a macro area & encoded by the gate's second estimation department according to the picture. If the internally encoded macroblock is larger than one, the internal quantization matrix and the interrelated quantization matrix must be updated, and the interrelated quantization matrix can be updated. Line editing ^^ S412: Use the new quantization matrix 1 '[v] [u] to perform step S414 on the current image. Check whether the current image is encoded. If it is, skip to step S4 02. If not, Then jump back to step S41. Step S4H: encode with a preset quantization matrix w [v] [u]. ~ Step S418: Check whether the current image is encoded. If it is edited, skip back to step S402. If it is not completed, skip back to step ^ 10: 70. In the above steps, 'If the encoded X image enters the adjustment mode, The matrix will be reduced by a factor of W / S. Since the macro block takes a new amount == ', when calculating the average quantization scale factor Avg_Q, the Q value of the 4 macro blocks is also reduced by 丨 / s times to reflect the actual Coding complex, and when the difference factor of the adjustment factor 3 of the adjacent image is changed, the quantization matrix is changed for each image to reflect the small difference. Therefore, the change of the quantization matrix can be performed in a case where the difference of the adjustment factors s exceeds one. In addition, there is a solution is to adjust the temple into the preset range, and calculate the corresponding quantization matrix. The adjustment factor SG can set four values such as UU, G.6 u, Q2, such as γ. The quantization matrices should be W1, W2, W3, and W4, respectively. ^ When the adjustment factor; s Gang Er _ _______7 —— _ Page 16 1221742 Number 92112855

V. Description of the invention (Π) When it is 0.67, 0.62, 0.54, 0.61 or 0.58, the updated quantization matrices are all W2 'and only the first image needs to be encoded into the bit stream, and the rest of the images The quantization matrix W 2 is also used until the header changes. FIG. 5 is a flowchart of a second embodiment of a quantization matrix adjustment method for improving image quality according to the present invention. The flow of this embodiment is that the encoder analyzes the current image in advance, and then performs the encoding operation of the current image. If the encoder can analyze the image in advance to collect the information of the complexity estimation, the encoder will more accurately decide whether to change the quantization matrix and how to change it. Generally speaking, the complexity of the current image can be estimated by performing motion estimation (m0ti ONX es t i ma t i on). For I-pictures, the var iance of each internally coded macroblock can be obtained. For p and ^ images, a mode decision must be made based on the difference between the internal coding and the interrelated coding modes. The sum of the differences is generally referred to as the activity of the current image. Before encoding the image, the encoder can obtain the degree of activity Act-C of the image. After the image is encoded, the average quantization scale factor Avg-Q and the actual bits BB ~ χ can be used to calculate the complexity of the image. ^ When the encoder cannot pre-analyze the current image of the image, the exhaustion device only decides whether to change the quantization matrix and change it according to the previous decoded image. , But when the image content of two adjacent pictures changes rapidly, the decision of this method may be wrong. For example, when the average quantization scale factor Avg —Q of the current image is only slightly lower than the scale factor threshold ThQ-X, i will not enter the adjustment mode at this time. However, if the encoding of the current image is complicated ^ Backward = At the complexity of the previous image, the bit $ after encoding the current image will be far lower than the budget value, and the bit rate will be too low. On the contrary, if the previous case No. 1221742 was revised in the fifth month, the invention description (12). The complexity of the image is quite low, but the complexity of the current image is quite high. The quality is greatly attenuated. Therefore, the difference between the method of the second embodiment and the method of the first embodiment is that this embodiment estimates the current activity level Act-C of the current image in advance, and then estimates based on the activity level Act-C Calculation of measured scale factor EstQ — C. The calculation of the estimated scale factor EstQ-C is as follows:

EstQ-C = (BB-X / BB-C) * Avg —Q * (Act —C / Act —X) ··· (?) Where Act-X is the activity level of the previous image. The difference between formula (7) and formula (4) is that in formula (7), when calculating the measured scale factor EstQ-C, in addition to considering the bit budget value and the average quantified scale factor Avg-Q, it also considers the degree of activity Ac t. That is, when the bit budget value and the average quantization ratio_factor Avg-Q are all equal, if the current image activity is higher than the previous image activity, the calculated estimated measurement ratio The factor E st Q-C will be relatively increased, so that the bit rate after the current image encoding is not ready to exceed the bit budget too much. Conversely, if the current image's activity level is & the previous image's activity level, the calculated estimated scaling factor EstQ-C will be relatively reduced, so that the bit after the current image encoding = There will be too little budget value. After the estimated measurable scale factor EstQ — c is calculated incorrectly, the second embodiment is the same as the first embodiment, and both use the estimated measurable scale factor EstQ — c to determine whether to enter the adjustment mode. When the estimated scale factor EstQ — c is smaller than the ratio and the factor threshold value ThQ — χ, the adjustment mode is entered, otherwise it is treated as a general wedge ^ ^. The eighth, "Tian Xinba," I 量化 汲 汲 蚂 将 will preset the quantization f new quantization matrix. In the adjustment mode, the encoder will move one by one: · _ · __________ two:-1

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1221742 Amendment V. Description of the invention (13) The final average quantization scale factor of the image is increased to a safe value Sq_x, and the safe value SQ — X may be greater than or equal to the threshold threshold value ThQ_x. Therefore, the present invention will use an adjustment factor (ad juss) to reduce the preset quantization matrix, and the initial value of the initial virtual buffer occupancy will be reduced to dO X / S. This adjustment factor; ς soap, ^ ^ ^ n翌: u sub 3 is a value less than 1, and it can be calculated from equation (5). The new quantization matrix w is calculated. Because of the quantization matrix, Lv] [] The minimum value is limited to j. 浐, is 1, so W, [v] [u] will not be described repeatedly. The operation of the performance is the same as that of the first embodiment. As long as it does not deviate from the present invention ... but does not limit the present invention to variations or changes. To say 'the lamp manufacturer can make various 1221742 _ case number 92112855_ year month month revision _ simple illustration Figure 1 is shown in the MPEG-2 specification The preset quantization matrix defined for the internal block. Figure 2 shows a schematic diagram of the VBV buffer in the CBR operation mode. Figure 3 shows a schematic diagram of the VBV buffer in the VBR operation mode. Figure 4 shows the quantization matrix adjustment for improving the image quality of the present invention. Flow chart of the first embodiment of the method. Figure 5 shows The flowchart of the second embodiment of the quantization matrix adjustment method for improving image quality of the present invention.

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Claims (1)

6. Scope of Patent Application Compilation 1 · A quantization matrix adjustment method for improving image quality, which encodes a series of images with a ^ codec, which has a preset quantization matrix. The adjustment method includes the following steps: · Update the used bit quantity and average quantization scale factor; specify the bit budget value for the current image; meaning, calculate and measure the scale factor, based on the used bit quantity, the second-mentioned average quantization scale factor, and The aforementioned bit budget measurable scale factor;: determine whether to enter the adjustment mode, when the aforementioned measurable scale factor is lowered to a lower scale factor threshold value, then the coding mode is set to a rounding mode, otherwise it is maintained as a normal mode; the adjustment quantization Matrix, when the encoding mode is set to reduce the quantization matrix; m Μ, pre-encode the image. When the encoding mode is the adjustment mode quantization matrix $ 彳 stomach f 彳, expression, according to the reduction, according to the preset The quantization matrix performs image coding. In the normal mode, 2 · As set out in item 丨 of the scope of patent application: moments, methods, in which the foregoing calculations are included; the changes are included in ^, and the measurement scale factor is estimated separately. Two-item household matrix adjustment Fang Banganshi 1 Jin Xiongzai's improvement Yingjunkou @ ΛΑay μ private sign-in method 'wherein the above-mentioned transfers the amount of the child such as the gurus and mound mouth I, coming in, and the small preset In the measurement, it is based on 4. As described in item 3 of the patent scope _ "Average 己 * average quantization scale factor for improving image quality. Πbits / bit budget value) 1221742 case number 92112855 Sixth, the adjustment scope of the patent application matrix: go, where in the aforementioned step of adjusting the quantization matrix, the aforementioned adjustment factor is the ratio of the aforementioned estimated measurable scale factor to a safe quantized scale factor. The recorded quantization matrix adjustment method for improving image quality, wherein the aforementioned safe quantization scale factor 6. As described in the patent application; the quantization matrix adjustment method for improving image quality described in item 4; Preset adjustment factors, and a plurality of corresponding reduced quantization matrices, when selecting the reduced quantization matrix that is the most adjusted among the preset adjustment factors and ^^ enters the adjustment mode as one of the reduced V-decay factors corresponding to 7 · -A kind of matrix to improve the image quality. The encoder edits a series of images. The matrix adjustment method is an array. The adjustment method includes the following + 4 encoders have preset quantization moments to update the used bits. Element quantity, front-band, and average quantization scale factor; Activity degree of an image, Act-X, activity of counting the image of a specified bit of the current image; J2, c; Factors, / ~ The aforementioned average quantization scale factors, A, ', are based on the previously used bit amount and the aforementioned bit budget value I, and then describe the activity levels Act_X and Act —C to determine whether to enter the adjustment mode! "! ^ Example factor; In a quantized scale factor gate value, the estimated scale factor is low, otherwise it is kept as a general formula. 'The encoding mode is set to the adjustment mode to adjust the quantization matrix'. When encoding, the town is An integer mode, the pre-1221742 Set the quantization matrix to be reduced; and the amount afterward is based on the ratio of the front of the transformation matrix (activity 9 · transformation matrix 1 adjustment 10 transformation matrix adjustment factor 仃 circle 诼 coding, mama matrix modeling image When encoding, ",", and "Bin", according to the reduced size, the EM and the missing codes are used, and the image is encoded when the quantization matrix preset by the encoding mode is used. The general mode is the same as the 7th adjustment method in the scope of patent application. Among them, the foregoing calculations include steps to improve the quality of the image and estimate the steps of measuring the scale factor Y 'and the scale factor. The degree of activity Act — C / activity level Act (pre 2 values), as described in the patent application No. 8; Second, the scaling factor. The adjustment method, in which the aforementioned adjustments are described as follows: the quantitative factor of good image quality to reduce the preset quantization moment 'in the step of the transformation matrix' is based on the 9th adjustment method of the scope of patent application, In the middle of the basin, f is thin / loaded, the steps of improving the image quality of the quantum Λ before, f from /, and the quantization matrix of the void are described in the previous section as a different estimate of the measurement ratio: Township $ ^. Μ 于 兴 女 全Quantitative scale factor A .π The method for adjusting the quantization matrix of the 10th item in the profit-seeking range, δ in A, 5+, and 1 of δ have been used to improve the quality of the image 1 2. For example, the scope of the patent application for the safe range of the scale factor is 6. Quantization The matrix adjustment method is recommended to improve the image quality: as well as a plurality of correspondences: reduction:;: containment; when several preset adjustments I are selected, the selection of the best adjustment factor in the preset adjustment factors enters the adjustment. The reduced quantization matrix of the pattern is used as the reduction: ";: Description: the integer factor-the set of pairs in ^ ^ Ί" Jun Zhi's placement matrix. • As described in item 7 of the scope of the patent application, the matrix adjustment method can be used to improve the image quality of the first 5 years: 1221742 _Case No. 92112855_ 年月 日 __ VI. In the step of applying for the scope of patent Ac t _C, for the I image, the difference between each internally encoded macro block is obtained, and for the P and B images For example, the mode judgment is performed according to the difference between the internal coding and the interrelated coding modes, and the sum of the differences is the current activity level Act_C of the image. Page 24