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1.
In order to improve the rate control performance of video encoder, video frames are segmented into two regions according to the video content, i.e. the foreground region containing the main moving objects and the background region containing the relatively static scene. The rate-distortion properties of the two regions are analyzed. Based on the analyses, a novel region-based macroblock layer rate control method for H.264/AVC is proposed. For the bit allocation process, more target bits can be assigned to the important macroblocks by employing an adaptive factor determined by the region information. Then, the quantization parameter (QP) is computed by using the quadratic model with different parameters related to the two regions. The computed QP is further adjusted to suppress the coding quality fluctuation between the two regions, as well as the quality fluctuation among the consecutive macroblocks. Finally, the rate control parameters are updated after coding the current macroblock. Experimental results demonstrate the mismatches between the actual coding bit-rates and the target bit-rates are reduced, while the coding performance of the encoder and the subjective visual quality of the reconstructed video are improved.  相似文献   

2.
It is very essential to extract representative frames in the process of generating video summary. A method is proposed which analyses the color features of the video frames, sets the connectivity threshold values automatically according to the contents, extracts the color coherence vectors (CCV) and then performs adaptive clustering based on equivalent relation. After global partition, local partition was revised with time sequential features. The whole process does not need to set any threshold values. The experiments with diverse videos yields effective results.  相似文献   

3.
Collecting real-time traffic flow information is a foundational function in intelligent transportation systems. Video based traffic monitoring system has advantage of installation and maintenance, so it iswidely used for traffic monitoring on main road and crossroad. Shadows result from roadside building or trees are one of the factors that arise errors in video based vehicle detection. An improved method based on edge information is proposed for vehicle detection and shadow rejection. Finally vehicle counting is achieved based on the edge detection method.  相似文献   

4.
A fast median filtering algorithm basing on the coherence of data in adjacent windows is presented.During median filtering,only the first median value is found by conventional squencing algorithm,the other median values are obtained by bisecting search method and quickinserting new element in sequenced window.For convenience of moving filter window along signal data,a data structure is desinged,which can make the new input element to cover output element and greatly reduce the quantity of computation.A 2-dimensional fast median filtering method by moving filter window along snack path is also introduced.  相似文献   

5.
Based on simulation and numeral recognition of the 24-bit bmp images of postal codes obtained by CCD transducer, a binarization method based on coloring matter is proposed, which is employed to extract the binary image of the frame line of postal code and the binary image of the mail character separately. The procedure of image processing is analyzed, which includes detecting and separating borderlines of postal code frames, image binarization, smoothing noise-removal, slant rectification, extraction of postal code numerals, position normalization processing, subdivision of digital image, feature extraction of character recognition, and so on. The pretreatment process of image recognition is described. Then, character feature extraction is conducted for pretreated images, while the angle correctness for postal code frames and characters is performed. Finally, the recognition result is determined. In this method, the difficulty of separating frame line from postal code character line is eliminated. In order to improve recognition rate, the combination of many methods of handwritten numeral is used, resulting in improved recognition rate of postal codes. The experiment shows that this method can obtain higher recognition rate, providing reference for the separation technique in postal system.  相似文献   

6.
An improvement method is given to detect small weak targets. It predicts the background gray and the actual gray of the current pixel molded by two predicting windows. The method can not only solve the edge blur problem of the traditional method, but fit for the detection of the bipolar targets. It can perform at a high calculation speed, which is an important improvement in the filed. In the process of real-time missile-tracking. The reliability and stability of detection require that the method cannot only solve the edge blur problem of the traditional method, but work well with the background no matter it is bright or dark. According to the experiment using the images provided by DX-1 missile-tracking project, the method is proved effective.  相似文献   

7.
It is possible to get high compression rate for the interrelationship between neighboring frames of moving pictures. The kernel of research on video compression is that the efficient image compression algorithm is adopted while the interrelationship between neighboring frames and time consumption is concerned to improve the compression efficiency. It is significant that motion compensation is applied to video compression, nevertheless it is too time consuming. A vector coding method based on wavelet transform is presented to avoid searching procedure of motion compensation. Simulation shows that high compression rate is achieved with less time consumption.  相似文献   

8.
对草莓、胡萝卜复合果蔬汁生产工艺及其成品稳定性进行了研究.采用正交试验设计出的最佳配方:胡萝卜汁与草莓汁重量比1:3,蔗糖添加量10%、柠檬酸0.15%、蜂蜜8%、黄原胶0.10%.该工艺生产的饮料色泽明亮,口感清爽,富含有机酸、氨基酸、维生素和矿物质,具有胡萝卜、草莓双重营养价值与保健功能.  相似文献   

9.
To improve the head detection accuracy in video sequences captured with fixed vertical monocular camera, a novel method of head recognition based on mean shift and multiple features is proposed. Firstly, mean shift based image segmentation algorithm with color information and spatial information is suggested to derive the candidate head components in images. Furthermore, by referring to two features that the contour of human head regions are approximate round and the hair color distribution is clustered, the evaluation models based on the contour information and inside color information of candidate head components are presented for head recognition. The experimental results show that the proposed algorithm can effectively reduce the light interfere and eliminate fake target whose color information is similar to hair color distribution. The detection rate for static images can reach about 89.4%.  相似文献   

10.
An image edge detection algorithm in fuzzy domain is proposed, which combines adaptive fuzzy enhancement and multi direction fuzzy morphology to detect the edges of fuzzy image. The adaptive fuzzy enhancement method enhances the fuzzy image within blocks with sliding windows to avoid losses of the real edges resulting from enhancing with single threshold for the whole image and lead strong adaptive ability to image region variance. The multi direction fuzzy mathematical morphology operates on the enhanced fuzzy image with structure elements of multiple different directions to extract the real edges with directionality and restrain non directional noise. Experiments show the algorithm can detect fuzzy image edge effectively with strong antinoise ability.  相似文献   

11.
When self-scanned photodiode array image sensors are applied in object measurements, the outer sizes of the object are included in the video signal of image sensors. The identification and measurement of the object ,and the enhancement of the performance is depended on the symbol extraction of the video output signals. Based on the working principles of self-scanned photodiode array image sensors, the mathematical models of image sensor's video signals are established when the moving object is captured. The comparative method and the measurement error are researched. The results of this paper provide a theoretic basis for the research of video signals processing.  相似文献   

12.
We research fractal characteristics of ECG signal, and find that it is logarithmic linear relationship between the boxes number covering signal and box scale. It is shown that ECG signal have some characteristics. Further more, we discover that fractal dimensions at QRS site are higher than others when using a time windows to detect signal. Based on this foundation, we raise a location algorithm of QRS waves which is based on fractal boxes dimension detection methods. The application results of this algorithm show that it can get rid of noise in ECG effectively with high speed, so this algorithm can be used in real time detection of ECG signal.  相似文献   

13.
The edible mushroom Agrocybe chaxingu was stored in packages with or without silicon gum film windows in three different modified atmosphere systems (5% O2, with 5%, 10% and 15% CO2) at a temperature of 3 ± 1 °C. The results showed that there were significant differences between the packages with and without the silicon gum film windows on O2, CO2, and ethylene concentrations, respiration rate, ascorbic acid content, electrolyte leakage and sensory characteristics. Compared to the packages without the silicon gum film windows, the packages with the windows were more effective for quality keeping of the stored mushrooms. This window kept the gas compositions of the packages at levels which avoided anaerobic respiration and resulting off-odors. Among three different modified atmosphere systems, the packages with the silicon gum film window with initial gas concentrations of 5% O2 and 10% CO2 were the most effective for maintaining mushroom quality.  相似文献   

14.
Aiming at the scheduling problem for jit delivery under the pulling type production, an optimal method for flexible job-shop scheduling problem (FJSP) based on demand time window is proposed. According to the demand time window of every workpiece, an optimal model for FJSP is constructed to maximize the average membership degree based on the completion time for every workpiece.Then, a tabu search algorithm based on multi-stage hybrid mutation is proposed and designed.To improve the convergence of the algorithm, inverse order mutation and gene segment swap mutation are used to find a good original solution, upon which gene swap mutation is used to find the optimal solution. The effectiveness of the proposed method is validated by applying to a multi-type and small-batch production manufacturing workshop.  相似文献   

15.
The marching cubes (MC) is an effective surface rendering method in three-dimensional visualization for medical image sequence. However, most existing MC algorithms are slow and inefficient because they have to process all the cubes for isosurface extraction. An efficient MC algorithm is proposed by combing the case lookup table and a novel adjacent lookup sub-table to exclude unrelated empty cubes. By explicitly building the fix-length adjacent lookup sub-table that is independent on image sequences, the volumes elements are constrained to those only intersect with the isosurface. Both execution time and temporary storage space are further reduced by incorporating the heap data structure in algorithmic implementation. Experimental results on human head, chest foot CT data sets by using the visualization toolkit package show that the traversal cubes decreases by 95%, and the reconstruction time decreases by 20% without any loss of reconstruction quality. Therefore, the proposed method can remarkably speed up the rendering time and be easily integrated into 3D visualization for clinical application.  相似文献   

16.
The proportion of radiation load through glass windows in building energy analysis is comparatively great;it is regarded as linear relation with temperature in BIN method,which is extremely a rough method.It is not only because the relation between such radiation load and temperature is far from linear relationship,but also there is lack of objective standard for the selection of corresponding representative temperature to the load.To solve this problem,calculating the maximum factor D_(J max) firstly,then get the hourly corresponding relation of load and temperature by multiplying the hourly cool load coefficient.The practical relation of load and temperature could be obtained by counting up the average load to each temperature at each direction;the load calculation method is still simple using a series of statistic data.A comparison has been made between this method and the former one.As it is the real reflection of relation between the temperature and load,the precision of load calculation is enhanced.The process using this method to calculate load for south facing window in Chengdu is given in this paper.  相似文献   

17.
Hydroxypropylmethyl cellulose(HPMC), Sodium Chloride and pure water were adopted to develop green cellulose ethers thermotropic materials. And thermally induced switching temperature, visible and solar direct transmittance were measured under different mixing proportion. For energy consumption, DeST h was used to study the energy efficient effect of thermotropic double glazing windows with different mixing proportion. It was shown that the optimum mixing proportion of hydroxypropylmethyl cellulose(HPMC), Sodium Chloride and pure water was 2:15:100 by mass. And thermotropic double glazing window can reduce energy consumption by 3% and 8%, respectively, when compared with Low E double glazed window and common double glazed window in hot summer and cold winter zone.  相似文献   

18.
水产品中农药残留检验检测方法研究进展   总被引:1,自引:0,他引:1  
我国是水产品生产和消费大国,水产品已经成为我国居民获取动物蛋白质的重要来源之一,但是大量不规范使用农药使得农作物和水源被污染,被污染的农作物和水源再将残留的农药富集到水产品中,从而造成水产品中农药的残留。水产品的质量安全对国民身体健康至关重要。本文着重介绍水产品农药残留检测方法的研究进展,突出分析水产品中农药残留的前处理方法。通过比较,认为采用乙腈作为提取剂的固相萃取前处理方法及气相色谱检测方法更能有效检测水产品中的农药残留物质。  相似文献   

19.
植物叶绿素含量不同提取方法的比较研究   总被引:3,自引:1,他引:2  
为探索不同提取液提取爬山虎叶绿素的效果,分别采用80%丙酮溶液、96%乙醇溶液、90%乙醇丙酮混合溶液、95%乙醇丙酮混合溶液四种提取溶液来提取五叶爬山虎叶片叶绿素。结果表明:叶绿素溶液吸收峰的峰值和不同提取液对植物叶绿素的提取能力随提取液的不同而不同,由大到小排序的顺序为95%丙酮乙醇溶液>90%丙酮乙醇溶液>80%丙酮>96%乙醇,相比于研磨法,用试剂浸泡法的叶绿素提取效率更高,这可为准确提取与检测植物叶绿素的提供一定参考作用。  相似文献   

20.
采用基质固相分散萃取-气相色谱(MSPD-GC)技术,建立丹皮中有机氯和拟除虫菊酯农药多残留分析新方法。以回收率为指标,采用正交设计优化选择填料种类,样品与填料量的比例、淋洗液的极性。丹皮样品与中性氧化铝(m/m,1:2)充分研磨5 min后装入10 mL玻璃层析柱内,通过10 mL乙酸乙酯洗脱,11种农药在0.02、0.1、1 mg/kg 3个添加水平的平均回收率为77.69%~110.7%,相对标准偏差均低于11.6%,方法检出限在0.1~3.4 μg/kg范围。该方法可同时监测丹皮中有机氯、拟除虫菊酯类等农药的残留水平,方法简便。  相似文献   

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