82results about How to "High compressibility" patented technology

The method includes following steps: scanning DCT coefficient blocks according to sequence so as to obtain last one nonzero coefficient (NC) and the coefficient in front of the last one NC in coefficient block, and number value of NC; based on the number value of NC to calculate difference value between number value of NC in this block and number value of NC in adjacent block, and constructing context model for number value of NC; calculating flag bit of NC for last one NC and coefficients before the last one NC; selecting context model to encode flag bit of NC; subtracting 1 from absolute value of NC according to scanning sequence or scanning inverted sequence; and selecting context model to encode number value of NC, and its position in the scan etc; encoding sign bit. The invention also discloses corresponding decoding method.

The invention provides a method and a device of multiple description video coding based on a relevance optimization rule, belonging to the field of video coding. The device comprises a coder, a decoder, a channel 1 and a channel 2, wherein the coder comprises a similarity optimization rule module, a preprocessor, an odd and even frame separator, a standard coder 1 and a standard coder 2; and the decoder comprises a standard decoder 1, a standard decoder 2, an odd and even frame interleaver and a postprocessor. The video coding method better keeps time domain relevance in a video subsequence by using the relevance optimization rule aiming at different motion information on the premise of guaranteeing the compression performance of each video sequence, thereby ensuring that a one-way decoder can more effectively restore lost information so as to improve the reconstruction quality of the one-way decoder.

The invention discloses an enhancement type bi-directional motion vector predicting method aiming at interframe predictive coding in a mixed video coding framework, comprising the following steps of: (1) solving an alternative set containing a plurality of bi-directional motion vector prediction values through an prediction operator by comprehensively utilizing the time domain correlation and the space domain correlation of motion information for a current coding module; and (2) selecting an optimal motion vector prediction value from the alternative set by adopting a self-adaptation motion information prediction selection method to carry out subsequent coding computation and decoding computation as the motion vector prediction of the current coding module. The invention enhances the prediction accuracy of a final motion vector by comprehensively utilizing the correlated characteristics of the motion information on time domains and space domains and can independently complete on coding and decoding ends without detuning by utilizing a self-adaptation selection technology based on a prediction coding block SAD standard, thereby enhancing the compressive property of the bi-directional interframe predictive coding and being widely used for the field of mixed video communication.

The invention relates to a Bayer image compression method based on YUV conversion, which belongs to the technical field of an aerospace optical remote sensor and is a Bayer image compression method used for an aerospace optical remote sensing CMOS camera. The method comprises the following steps: carrying out space conversion on a Bayer-format image from a three-color space to a brightness-chroma space, eliminating the relativity among the three color components to be ready for different compression ratios used by brightness and chroma, self-adaptively determining the compression ratios based on the complexity of the image, carrying out line conversion and encoding. The invention greatly improves the quality of the compressed image by carrying out space conversion to eliminate the relativity among the three color components, and further enhances the adaptive capacity of the camera by using different compression ratios for images of different complexities.

To mix video signals of plural channels in time division and record these video signals onto a recording medium, as well as to select and transmit the video signal of a specific channel to a terminal device at a remote location, there is a video signal switching unit for mixing the video signals of the plural channels in time division; a first video signal compressing unit for compressing the mixed video signals from the video signal switching unit; a unit for recording the video signal compressed by the first video signal compressing unit into the recording medium; second video signal compressing units for selecting a channel from the mixed video signals and compressing the video signals with a compressibility higher than that of the first video signal compressing unit; and a unit for transmitting the video signal compressed by the second video signal compressing unit to a remote location.

A high-shock-resistance artificial quartz stone sheet material comprises the following raw materials: 16-100 mesh quartz sand, 300-1000 mesh quartz powder, an adhesive and a pigment. A preparation method of the high-shock-resistance artificial quartz stone sheet material comprises the following steps: (1) adding quartz sand into a mixer and uniformly stirring at a low speed, then adding quartz powder and stirring at a low speed for 15-25 s, and then performing high-speed stirring for 30-40 s to obtain a mixture; (2) doping the pigment and an auxiliary agent into the adhesive, stirring, pouring into the mixture obtained in the step (1), and performing high-speed stirring for 50-60 s; (3) further dispersing the mixed material through beating, metering and sending to a material distributor for material distribution, and then sending to a plating die, sending the plating die into a molding press and molding under the conditions of vacuum, shaking and pressurization; and (4) curing the molded sheet material, and after curing is finished, performing thickness setting and polishing deep processing. The high-shock-resistance artificial quartz stone sheet material has the advantages of brilliant color, good shock resistance, high compressibility, high bending strength, uneasiness to crack, resistance to scratch, good compactness and the like.

The invention discloses image and digital video coding and decoding methods, and belongs to the technical field of digital image processing. In the coding and decoding methods, when two-dimensional forward / inverse discrete orthogonal transformation is carried out, two-dimensional integer forward / inverse discrete Tchebichef transformation is adopted. In the invention, the two-dimensional integer forward / inverse discrete Tchebichef transformation is used in place of other integer transformation method used in the prior art, so that the method can effectively solve the mismatch problem of a decoder, realizes lossless coding, and has high compression property and high expandability. The invention further provides a fast algorithm of 8*8 integer discrete Tchebichef transformation matrix; and the algorithm only needs shifting and addition operation, so that the consumption of hardware resource is reduced, and hardware realization is facilitated.

The invention discloses a method for manufacturing a composite material component. The method comprises the following steps of S1: coating the side wall of a cavity of a die with a demolding agent; S2: paving a prefabricated body in the cavity: S21: paving continuous fibers on two layers on the outmost surface of the prefabricated body, and arranging a combined paved layer structure of the continuous fibers and chopped fibers between the two layers of the continuous fibers, and S22: positioning the prefabricated body in cavities formed in an upper die board and a lower die board, and performing high-temperature compaction; S3, sealing the upper die board and the lower die board for die assembling, locking the upper and lower die boards by a locking bolt; S41: heating the die to required glue injection temperature; S42: vacuuming through a glue outlet until the vacuum environment is stable; S5: injecting resin into the cavity, closing the glue outlet and a glue injection opening after the glue is completely discharged from the glue outlet, and stopping glue injection; and S6: heating and solidifying the die, and demolding to obtain a required product. The method has the beneficial effects that the composite material component meeting the requirement on the appearance is manufactured, so that the product is unlikely to deform, and the processing cost can be effectively lowered.

The invention relates to hyperspectral image compressing and restructuring device and method. The method includes steps of firstly, subjecting each spectrum range of a hyperspectral image to three-level two-dimensional 9 / 7 integer discrete and lifting wavelet transformation; organizing wavelet coefficients to sections and blocks through CCDSD-IDC, encoding section header information and DC (direct current) coefficient initializing and AC (alternating current) coefficient depth of each block, extracting AC coefficient and residual DC coefficient bit plane simultaneously, and finally subjecting the AC coefficient and residual DC coefficient bit plane to distributed signal source encoding by a Slepian-Wolf encoder based on LDPC (low density parity check). The hyperspectral image compressing and restructuring device and method have the advantages that by adopting distributed signal source encoding strategy, complexity of the integral encoder is lowered, and the method is easy to implement through processors such as FPGA (field programmable gate array) and DSP (digital signal processor).

The invention provides a large-scale MIMO channel feedback method based on PCA evolution. The method comprises the steps of firstly acquiring related characteristic parameter of a downlink channel and building a channel model in view of channel characteristics in a space domain and a frequency domain; secondly, clustering channel state information after vectorization, and improving correlation and compression of the channel state information thus reducing high-dimensional channel state information to low dimension; then, computing a covariance matrix and a sparse matrix of the channel state information in each cluster of a characteristic parameter channel model at a receiving and a transmitting end; further extracting a main component of a sparse vector via a selection matrix at the receiving end, thus allowing the selected sparse channel vector to meet a principle that the sum of each element is maximum; and at last, feeding the selected parse channel vector and a codeword index of the selection matrix back to the transmitting end. The method provided by the invention reduces a lot of feedback quantities and computation complexity while acquiring relative high accuracy based on a PCA thought and a clustering thought.

The invention discloses a distributed optical fiber sensing big data real-time statistical compression method, and relates to the field of sensing signal compression technology. The method comprises the following steps: 1, taking one-dimensional time response signals accumulatively acquired for a long time by each space point in a whole monitoring range as measurement signals, and performing quantile statistics for the measurement signals of each space point respectively; 2, determining an abnormal signal decision standard of each space point according to a quantile statistics result; and 3, taking a one-dimensional time response signal accumulated in a certain space point for a period of time as a signal processing unit, and making an abnormal signal judgment on the signal processing unitaccording the abnormal signal decision standard of the space point; if the signal unit is an abnormal signal, performing a data compressing operation on the signal processing unit. Through adoption of the method, the compression efficiency of massive data generated in a continuous space-temporal uninterrupted monitoring process is increased greatly, and the real-time performance requirement of the massive data compression can be met.

The invention discloses a preparation method of high-manganese non-magnetic steel powder. The preparation method comprises the following steps that (1), steel scrap of plain carbon steel and steelmaking pig iron are taken as raw materials, and secondary materials are added for smelting; (2), refining is carried out after the steel is smelted, metal manganese and ferrosilicon are added, and pre-alloying treatment and deoxidation treatment are carried out; (3), high-pressure atomization, dehydration and drying treatment are carried out on the refined steel to prepare primary powder; and (4), high-temperature reduction, crushing and sieving treatment are carried out on the primary powder to obtain the high-manganese non-magnetic steel powder. According to the preparation method, the plain carbon steel scrap steel and the pig iron are used as the raw materials, the high-manganese non-magnetic steel powder with proper loose packing density and good pressing performance is prepared by adopting a water atomization method, and the method is suitable for production of high-density and high-strength powder metallurgy non-magnetic structural parts.

The invention discloses a unidirection control combined power adjustable air inlet way and a design method thereof. The air inlet way is composed of a first-stage bending compression face, a second-stage bending compression face, a fixing lip cover, a throat equal straight section and a square-to-round expansion section. The unidirection control combined power adjustable air inlet way is characterized in that a hook face+wedge face combined external pressure section wave system combinatorial arrangement is provided and is applied to a binary supersonic velocity air inlet way external pressuresection top plate rotating variable geometry scheme, it is guaranteed that the combined power adjustable air inlet way can normally work under all mach numbers, meanwhile, the contradiction that consideration cannot be given to supersonic velocity air inlet way low mach starting capacity and high mach number aerodynamic performance is avoided. The adjustable second-stage compression face is a unique motion component of the overall air inlet way, and one motor is used for achieving unidirection control over two geometrical parameters including air inlet way second-stage compression angles and the throat height.

The invention relates to a compound building foundation using waste steel residue, which is a building structure style, comprising the style that modified part is combined with the raft foundation or the strip foundation, the lower part is cylinder modified part, the middle part is shallow modified part and the upper part is raft or strip foundation of reinforced concrete; the style that modified part is combined with the independence foundation, the lower part is shallow modified part and the upper part is the independence foundation. In the invention waste steel residue is used to improve the soft soil so that the rigidity of improved soil is less than the one of pile, meanwhile the improved soil is provided with relative bigger viscosity and certain compressibility. It can absorb the energy of earthquake wave efficiently and achieve the no-shake effect.

The invention belongs to a composite material high performance technology, relates to toughening material of composite material and a preparation method of the toughening material. The toughening material is made of non-woven cloth comprising thermoplastic polymer fiber, the thickness of the non-woven cloth is 5 to 50 micrometers, and the fiber diameter of the non-woven cloth is about 0.2 to 5 micrometers. The preparation method comprises the steps as follows: yarns are sprayed out through solution; the yarns are deposited to become the non-woven cloth; and then the fiber non-woven cloth toughening material is formed through drying and collection. The method adopting a solution spray process to prepare the non-woven cloth toughening material can effectively improve the preparation efficiency, and realize the mass manufacture of the toughening material. The toughening material prepared by the method can obviously improve the compression performance of impacted resin matrix composites, and compared with the prior art, the method has the advantages that the compression strength of the impacted resin matrix composites is improved by 50 to 150 percent, the heat resisting property and the mechanical property of composite material, as well as the flowing of resin during the forming of the composite material, are not affected, and the yield and the quality stability of the composite material are improved.

The invention discloses a gravel pile and plain concrete pile combined composite foundation. Gravel piles and plain concrete piles are alternately arranged in a field needing to be treated, gravel cushion layers are paved at the tops of the piles, and the length ratio of the gravel piles to the plain concrete pile is 1:2. The gravel piles can effectively compact earth among the piles to solve the problem of uncompleted concretion of new fill stratums and can form drainage channels to achieve the effects of replacing and forming the drainage channels, and meanwhile, foundation liquefaction can be further eliminated by compaction vibration during construction of the gravel piles. The gravel piles, the plain concrete piles and an original natural foundation jointly form the combined composite foundation, and effects of compacting soil mass, replacing and forming the drainage channels, eliminating liquefaction and benefiting soil mass concretion are achieved while bearing capacity can be greatly improved and soil compressibility of the foundation is lowered. The gravel piles and the plain concrete piles are combined, disadvantages are avoided while advantages are complemented, treatment effects are guaranteed while the requirements of a superstructure are met, and effects of capital saving and project period shortening are further achieved.

The invention discloses a multispectral image compression system and method based on joint bit rate allocation and control, and mainly aims to solve the problems of instability of reconstruction quality and inaccuracy of JPEG-LS (joint photographic experts group-lossless standard) bit rate control caused by uneven bit rate allocation when multispectral images are allocated in the prior art. The method includes the implementing steps: performing KL (Karhunen-Love) conversion on a multispectral image to obtain converted components; performing data reconstitution on the converted components to obtain reconstituted components; and performing quantization step-size adjustment and quantization adjustment for the first time on all row data of the reconstituted components, performing iterative adjustment for the second time on quantified step size of last several rows, and performing quantization coding according to the quantified step size to obtain bit streams. By component data reconstitution and unified quantization step-size adjustment, bit rate allocation and bit rate control are combined and achieved, bit rate control precision is lower than target bit rate, reconstruction quality of spectral segments is uniform and stable, overall performance is optimal, and the method is suitable for various onboard multispectral image processing and transmission.

The invention discloses a stripper for a die for pouring an epoxy resin part of a GIS (Geographic Information System) basin-type insulator and a control device of the stripper. The stripper comprises two rails and a rotating device, wherein the two rails are arranged in parallel; male die fixtures are arranged on the two rails; two female die fixtures are arranged side by side with the two male die fixtures; and both the male die fixtures and the female die fixtures are driven by a pneumatic manner. The stripper adopts a pneumatic driving manner, so that equipment can be guaranteed not to have rigid impact in the long-term operating process; and meanwhile, by rotation of the rotating device, the working faces of female dies are towards workers and are convenient to wash. The control device comprises a plurality of pressure sensors and overflow valves, which are arranged at air inlets and air outlets of corresponding pneumatic components; each pressure sensor and a photoelectric switch acquire signals of the equipment in different working stages and a controller controls each pneumatic component to complete the corresponding working process; and when the pressure sensors at the corresponding positions work abnormally, the corresponding overflow valves take a pressure relief effect, so that safety working of each pneumatic component in the integral equipment is ensured.

The invention relates to an image compression method based on a direction lifting wavelet and improved SPIHT under the IoT (Internet of Things). The invention discloses an image compression method. The invention aims to solve a problem of low encoding efficiency caused by a case that an existing SPIHT method rarely considers edge blurs or a ringing effect caused by missing of high-frequency information and cannot retain more details in an image. The image compression method comprises the process of: 1, obtaining partitioned image blocks; 2, obtaining an optimal prediction direction of the partitioned image blocks; 3, carrying out weighting direction interpolation on a score sample value by calculating a weighting direction interpolation filter coefficient so as to obtain interpolated imageblocks; 4, respectively carrying out wavelet transform based on direction lifting on the interpolated image blocks by utilizing the optimal prediction direction so as to obtain each transformed imageblock; 5, forming an integral transformed image by all the transformed image blocks; and 6, by utilizing an improved SPIHT method, carrying out encoding on the transformed image obtained in the step5 so as to obtain the encoded image. The image compression method is used for the field of image compression.

The invention provides a two-color fine-particle artificial quartzite board, which is prepared from the following raw materials including quartz sand being 16 to 26 meshes, quartz sand being 26 to 40 meshes, quartz sand being 40 to 70 meshes, quartz sand being 70 to 100 meshes, quartz being 325 meshes, quartz powder being 1250 meshes, silane coupling agents, curing agents, bonding agents and color pigments. The two-color fine-particle artificial quartzite board has the advantages that the production efficiency is high; meanwhile, the product rejection rate is effectively reduced; the mutual separation of colors can be realized; the mass production can be realized.

An automobile air conditioner rotary vane compressor preventing stop reverse rotation and leakage comprises a front end cover (1) and a shell (2). The front end cover is provided with an air inlet (4). The automobile air conditioner rotary vane compressor is characterized in that a check valve (5) is installed in the air inlet; the check valve comprises a plug (501), a valve piece (502), a spring (503) and a casing (504); the plug is in interference fit with the inner wall of the air inlet; the upper end of the casing is also in interference fit with the inner wall of the air inlet so as to prevent the condition that during use, airflow pulsation is caused by the fact that the casing rotates in the air inlet; the upper end of the casing is provided with a notch through which the plug can be pressed in conveniently and the upper end of the casing can be in interference fit with the inner wall of the air inlet; the circumferential wall of the casing is provided with air inflow openings; the lower end of the valve piece abuts against one end of the spring; an upper end seal cone of the valve piece abuts against the seal face of the plug; the other end of the spring abuts against the inner bottom of the casing; and an annular convex shoulder is sleeved with a coil axial limiting pressing plate. The automobile air conditioner rotary vane compressor is convenient to install and good in noise reduction effect.

The invention discloses a method of molding and manufacturing a cam by using Se-Sb-Zn-Mn series aluminum alloy as a material through powder metallurgy, and belongs to the technical field of powder metallurgy. The cam molding and manufacturing method comprises the following manufacturing procedures: carrying out blank molding through powder metallurgy, annealing, carrying out tempering treatment, machining, chemically treating the surface of the cam, and carrying out preservative treatment and polishing treatment, wherein the powder metallurgy process comprises the steps of annealing, screening, mixing and granulating, not only can improve the compressibility of powder and but also enables all components to be uniformly mixed, thereby improving the flowability and stability of the powder; the annealing and tempering treatment on the cam remove internal stress and refine structure grains; the cam is machined by milling; and a green pollution-free cutting fluid is introduced in a machining process, so that the environmental pollution is avoided, and the bodies of workers are free of pollution. The manufacturing method has the beneficial effects that the abrasion resistance of the cam is improved; and the corrosion of the cam is retarded by carrying out electroplating preservative treatment and polishing treatment on the cam in the end, thereby prolonging the service life of the cam and meanwhile improving the surface hardness, bending strength and heart toughness of the cam.

The invention discloses a trans-critical carbon dioxide refrigeration method and a device thereof. The method comprises the following steps that (1) superheated carbon dioxide steam is pressurized forprimary compression and primary cooling; (2) subcritical carbon dioxide is subjected to secondary compression and secondary cooling; (3) after supercritical carbon dioxide is cooled again, the supercritical carbon dioxide is throttled to be low-temperature subcritical carbon dioxide; (4) the throttled low-temperature subcritical carbon dioxide is sent to an evaporation tank to be evaporated intohigh-temperature low-pressure carbon dioxide gas; and (5) the high-temperature low-pressure carbon dioxide gas absorbs heat and then is converted into superheated carbon dioxide steam, and is fed intoa first compressor for boosting for cyclic utilization. According to the trans-critical carbon dioxide refrigeration method and the device thereof, an expansion machine is used for recycling and outputting mechanical energy to drive a compressor to complete compression, a double-compressor is used for improving the compression performance of the supercritical carbon dioxide, and a double-gas cooler and an internal regenerator are used for cooling the carbon dioxide gas so as to improve the cycle energy efficiency of the carbon dioxide.

The invention belongs to the technical field of sealing materials, and relates to a hysteresis heat generation accelerated vulcanization sealant. The sealant is formed by mixing two components, namely base paste and a vulcanizing agent, and the mass ratio of the base paste to the vulcanizing agent is 100:(8-12); and the base paste comprises the components in parts by weight: 100 parts of sulfydryl-terminated liquid rubber, 0-20 parts of filler, 10-100 parts of a magnetic nano material, 1-4 parts of an adhesion promoter, 0-5 parts of a vulcanization accelerator and 0-10 parts of a plasticizer, and the magnetic nano material is an alloy or an alloy oxide with the Curie temperature not exceeding 100 DEG C and a mixture of the alloy or the alloy oxide. According to the sealant, heat generated in an alternating magnetic field can be utilized to achieve local rapid heating so as to promote accelerated vulcanization of the sealant, the assembly efficiency is effectively improved, meanwhile, accurate temperature control can be achieved, the tensile strength performance of the material is high, and the onboard use requirement can be effectively met.

The invention discloses a multi-cutter extruder, which comprises a machine barrel, wherein the inside of the machine barrel is provided with an inner bushing, a screw and a closing type cutter; the closing type cutter consists of a dynamic cutter and a static cutter; the static cutter is connected with the inner bushing into a whole; and the dynamic cutter is jointed with a conveying threaded module. The improvement on the closing type cutter structure, an adopted new assembly method and the fixation of the inner bushing, the static cutter and the machine barrel with ballistic scrolling keys facilitate the adjustment of the position of the closing type cutter during actual use, so the extruder meets more actual production requirements. The high-precision cutter panel occlusal clearance ensures the elements obtain precise occlusal clearance in the screw, greatly improves the shearing performance, compressibility and dispersibility, and facilitates the detachment and installation of the screw.

The invention discloses a video decompression method and system based on Hog features and an lgb classifier, and relates to the technical field of video decompression. The method comprises the steps of converting a monitoring video of an unmanned convenience store into a plurality of frames of images; selecting a first frame image of the original monitoring video, performing pedestrian detection by using the Hog features and the lgb classifier, and removing the pedestrian positions to form a background picture without a moving object; carrying out the pedestrian detection by using the Hog features and the lgb classifier to find out the pedestrian positions, and cutting the pedestrian positions as the pedestrian pictures to be stored and named; comparing each frame of image contained in theoriginal video with the background image to obtain a difference value, storing the residual data in a linked list, and compressing the residual data; taking out the background picture, and decoding and restoring the background of each frame of image according to the residual data in the linked list; taking out the pedestrian images in the linked list to cover each frame of background image, and decoding and restoring all frames of images; and splicing all the covered frame images into a video according to the bit rate and the code rate of the original video to complete the video restoration.

The invention discloses a video compression method and a video compression system for an indoor monitoring scene, belongs to the field of video compression, and aims to solve the technical problem ofhow to perform effective video compression on an indoor monitoring video and improve video compression performance. The technical scheme is as follows: the method comprises the following steps: S1, selecting a key frame; S2, performing bounding box prediction and prediction classification on each frame of video image by using YOLO3-based target detection; S3, carrying out image matting on the bounding box predicted to be the person in the step S2, and carrying out compression storage on the matted person image in a jpg image format; S4, storing the number of frames and the position coordinateinformation of the personnel image in the original image in the form of a personnel image filename while storing the personnel image; S5, decompressing and reconstructing video. The system comprises akey frame selection module, a bounding box prediction and prediction classification module, an image matting and compression storage module, a personnel image storage module and a video decompressionand reconstruction module.

The invention discloses a rigid polyurethane foam composition, a rigid polyurethane foam material, and a preparation method of the rigid polyurethane foam material. The rigid polyurethane foam composition is prepared from the following components in parts by weight: 60-70 parts of polyether polyol, 30-40 parts of polyester polyol, 1-3 parts of water, 0.1-0.5 part of a catalyst, 1-3 parts of silicone oil, 0.2-1.5 parts of nano metal oxide, 0-10 parts of a foaming agent, and 110-140 parts of isocyanate. According to the rigid polyurethane foam composition disclosed by the invention, the nano metal oxide is added, so that the heat conductivity coefficient of the rigid polyurethane foam material is decreased compared with a traditional rigid polyurethane foam material, and further the compression performance of the rigid polyurethane foam material is improved; the heat stability is good, foam pores are fine, the dimensional stability is good, and the strength is high; the yellowing degreeof the rigid polyurethane foam material can be effectively reduced, the rigid polyurethane foam material is not liable to be yellowed, the attractiveness of the light-colored polyurethane material isnot affected, and the aesthetic requirements of people are met.

The present invention discloses an image encoding / decoding method and a device therefor. Specifically, an image encoding method may comprise the steps of: generating a quantized transform block by performing transform and quantization on a residual signal of a current block; splitting the quantized transform block into a plurality of coefficient groups; determining a first scan order representingthe scan order among the coefficients of the coefficient groups; and entropy encoding the coefficients of the quantized transform block according to the first scan order, and a second scan order representing the scan order among the plurality of coefficient groups.

The invention provides a point cloud data compression method and system based on projection and video stitching. The method comprises the following steps: analyzing the geometric attribute features ofpoint cloud data, determining a corresponding projection strategy, and determining an optimal projection angle; and projecting the projection areas at the same projection angle for multiple times toobtain a group of two-dimensional pictures with spatial correlation at the same angle. According to the invention, coordinate conversion is carried out on the point cloud data to adapt to a corresponding projection mode, and the problem of shielding of the intensive point cloud is solved in a same-angle multi-projection mode. According to the invention, projection pictures are spliced into a videoform; converting the single spatial correlation between the pictures into the temporal correlation between the video frames; point cloud data of a three-dimensional space is subjected to dimensionality reduction to a two-dimensional plane in a projection mode, projected pictures are spliced into a video format, then an existing coding tool is fully utilized for compression coding, the compressionperformance is improved, and the efficiency can be greatly improved by adopting the existing coding tool.