FR2499800A1 - METHOD AND DEVICE FOR COMPRESSION AND PRETREATMENT OF MULTISPECTRAL DATA - Google Patents

Abstract

METHOD AND DEVICE FOR COMPRESSION AND PRE-PROCESSING OF MULTISPECTRAL DATA. PROCESS FOR THE COMPRESSION AND PRE-PROCESSING OF MULTISPECTRAL DATA WHICH MUST BE TRANSMITTED FROM SATELLITES OR OTHER STATIONS. THE DIGITAL OUTPUT DATA OF THE MULTISPECTRAL SYSTEM IS COMPARED WITH MANY NUMBERED AND STORED SPECTRAS ON BOARD THE SATELLITE OR THE STATION AND ONLY THE NUMBER OF THE SPECTRUM THAT CORRESPONDS TO THE OUTPUT DATA IS TRANSMITTED.

Description

Method and device for compression and pretreatment

multispectral data.

  The present invention relates to a method and device for the compression and pre-translation of multispectral data to be transmitted from

satellites or other stations.

  In so-called multispectral camera systems used up to the edge of the satellites, the Intensities of the photographed image-points are measured in different spectral channels, generally in digital form.

  recorded on a memory element for the purpose of

data interpretation.

  In a 6-bit, 6-bit resolution camera system, about 6, 8 x 1010 different color shades are transmitted with the current method (with a data word length of 36 bits per picture point). The high number of color shades far exceeds the definition of

  colors which are technically rational or usable

  salers and drives too much data rates. By way of comparison, it can be stated that a shooting in

  black and white and high resolution resolution

  256 gray tones which corresponds to a length of

8-bit data words.

  The present invention therefore has as its object

  to develop a process and device of the above type

  which allow for a reduction and selection of

  data without affecting the quality of the data to be trans-

  to put. This result is achieved according to the invention by the fact that the digital output data of the multispectral system is compared to many numbered spectra stored on board the satellite or the station and which are not transmitted.

  that the number of the spectrum that corresponds to the output data.

  According to an advantageous characteristic of the invention,

  the comparative spectra are defined by values of lnten-

  The upper and lower limits in each spectral channel are determined and the correspondence between one of the stored spectra and the measured data is determined when this data is available. his eqo e; aqao anbsao 'I seaeld ep se4aos sap no se4unId sap aldwaxa aed' sgugwzaegp ss; eqop se.aioods Se enb jasiaomugw 9 at in9d uo 'aleizads uo $ qesjIr n at anod' $ uewmmeou '$ suIV * sSao; $ saquea $ I9jp e awts.6s el $ uawpidesa asedpe, p alq-ssod os 8I 'aqilte4s np paoq nee ueAnoq as aulmeaUoad unp aseq el Jns no Ios np illed q aGaomw9w el ap nuasquoo np uoieoIj $ pom aed enb xnaseuueA sanaiT T ad q Ie I saleu o0c -12TJO sauuop sap UOTSsTwSUea el DoAenb alqTej uuaw uaaw -aqTSsueSs se ea wmsueaq e saeuuop ap xnel aI 'sjTseaedwoo seaqoedsap psiaomww adnoa2 a sepansaw sauuop sep laoa sdwe! ua uojie0oossevI 4sa aelnolaled asesueael a9exaldlilnw ua j $$ lsodsTp el JauuolT g -ouoj iej uo 4a se9lqeo no saT4os g saalowpw sap esllqn uo uoUua & uj, ap aJeInOTaed ase aune uoleaS Aai4oeds a aealoosss eaqe 4nad eaJowpw el op seoTa $; w sap sauuoToD N sap aunoeuo anb slpue $ saquuop ep eT4ao ep seu $ ae esseapep S3u2T1 aoose uo ea $ omww 0o enbeqo ç $ 9 seganet seouuop sep oow np $ Iq np JnanSuoT se quegp a 'sciq N x, eJanpueS eI op a-gougw aw aSin uo Te 1oads ieuo enbqo inod 'saaTowpw sael suep uolsesiJowgw AND aoasjJe Ui UOIaUaAUl T UOleS JlTsodsTp ae Suna equepuodsa.Taoo aeaTeuq anaIeA sun ua aouaploujoo ap ieuSs St a0 @p oapwnu al ataJeAUO0O uo MEAU us 90uoW alJeuçq inapoo a suep Tunb saadeseanealedns $ asaanaeapju s! TI saw SJnaTeA set eaqua 9ulwaeasp easoeds a anod quemwueiTnwTs guen4Ts as saez.nsm sepuuop sep s3plsueaqu xneaioeds xneueo Sal sno4 suep Is aulJaeoap uo 'JIvnDosuoo GouOpTouZoo ap ot noalo a suep Sa sj $ aedwoo seafoods s4uaeapj $ p N xne seagoosse 4ue4e his; Lao sal 'sasTIesaed seouuop ep sal4aos N Qe aeowmw eun, p assaape, p seu2lT xne ssnbltd of 4ueweAI -oedseaJ uos xnea! oads xntueo s; suapJjj-p sap enb-awwnu wa.oj Eos ses1m se9uuop setl TanbeT suepJjjj-pwddsodsTp a asruoogad 9 UOlUeAUl, I pppooad ao op JAaneo ua aslw el anod ea $ oaeds np aJnealJ -, dns eaaTeaJul saATsoedsea seIwmlT SJinasA sap anaTi -9ul, q 4uenans ss xneaoeds xneuwo salt sno4 Su8p saaJnsem a 00866ta the heat on the surface of the earth. One can also consider as a particular advantage the fact that the access is so to speak forbidden to the third party, since the transmitted data are worthless if we do not know the spectra associated with the numbers of the transmitted spectra. The invention will be better understood using the

  description of an embodiment taken as an example, mals

  not shown, and illustrated by the accompanying drawing, in which: Figure 1 is an example for the definition of four different comparison spectra for a resolution of the measured 5-bit data;

  FIG. 2 is a circuit of principle for the com-

  paralson multispectral measured data; FIG. 3 is an example of the principle circuit according to FIG. 2 with the spectra indicated in FIG. 1; Figure 4 shows another example;

  FIG. 5 represents an example like FIG.

  For ease of understanding, it should be noted that the solution according to the invention is based on the principle

  that the standard multispectral measured data are compared

  data from a predetermined numbered group of normalized spectra. If we find a correspondence between

  measured data and a spectrum, we identify the data

  of this point-image by marking them with the number of this spec-

  and for further processing of the data, no

  or only record the corresponding spectrum number.

  As can be seen in FIG. 1, each of the comparative spectra is defined by intensity values

  lower and upper limits in each spectral channel.

  FIG. 1 represents an example of the definition of four different comparative spectra A-D for a resolution of the measured values of 3 blts. There is correspondence between one

  stored spectra and the data measured when these

  in all spectral channels are within the respective lower or upper limits of the spectrum. FIG. 2 represents a principle circuit for comparing the multispectral measured data with all the N aq: ue 4. in its SSSape ZGp sag; suaequ sBal uop Gaxowmw eU op uuemeuoedua xnV é.oeds a apaosse 4so atOW9pW el Op seolaJ4w sep sauoloo M sap aunoeqo '% 001 - 0 ep a IsTlewaou 9gIsuaguT, IT eSpaos op sau2; IN a (UV -; V)

  assaJePP saSil a DeAe esqgq N xa a nanpueaJ el el -

  a9Iow9um aun xnaep unaeqo nod asi; Zn uo 'lIeaoads leuea & ed sfq H op sainsaom saauuop sap uo; nlos9 aounnod Where To go to the site of the company, its sjleazdwoa so, oads se not. oaaJaJ aai qnad gnbTpu gnaolo aeI ESOs uoIqlIgdo a + gO * 9a5slIi4n laîp9ew al uoeaS sagansmw s.tlaliA thirteenth 9Taosse gi J; igearIoo ogaodas np oagwmnu aI aueuwaegp uo has saslJomwgw sj $ igeaedmoo saaoaads sael Snoa P saginsam sapuuop self ajedwoa uo aowopm el. saaoe Inas a joeie aqapdqgp aG o DaAv aeuvpuodsaezoa oaieuq JnaieA ua IUSIs ao ap r OIaltnU aI gtgJ3AuoD IVAe Aa 9gUO0m, where do you inapoo or 0o enbpoIe if sea and seafarers alike? (N; I> 1) Id IUIs to sea 4sOo IS saJneJagdAs go saonanolgjuT sa! Lw sfnelvA sao oagueWeqltUTs ssue as aplaqaed unp srsueou; seI xtie.xgoads xneueo se- snog suep Is aulwaepp jf $ inosuoo aouoplou0oo ap1no.Ilo el 9I 0 aulieA ei uu !. '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' '' ',' '' '', that it had been a year since it had been algaos op sau2Tt soil saenoa onb UQoej ap saalowaw 0I soT suep sgsl.owgw $ uos sjg-eaedwoo salgoeds sar sjTizea.dwoo seagoeds sguoa18JjiP N xne saploose juos Nb - tb saiajos N sael sol -qllîe.d saI.JOs N 1 w oJTOw9w aun , * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Gpoo oagmnu np uolSuuleaa4gp el go aITomw3 el savoe Inas a xed sassaoweu sJlIeaedwoo soagoads 9î 00866tZ the lower and upper limit values of the spectra

  comparisons, the corresponding matrices are stored in the columns.

  for example a 1, and if not a 0. FIG. 3 represents an example of the contents of the memories of the spectra selected in FIG. 1. FIG. 4 represents a device by which the data of 6 spectral channels are associated by an access of the memory 16 with different comparative spectra. In this device,

  it is assumed that wired OR output memories are used.

  If, for example, the scanning time of a point-

  image is at least 16 times greater than the access time to the

  In FIG. 5, an example of a multiplexing device, that is to say 16 accesses to the memory by image point, is shown associating the multispectral data of 6 channels.

  at 1024 different spectra. Here, too, we use

  moire with outputs OR wired. It is clear from what

  precedes that the number of desired color nuances is pre-

  determined by the number of comparative spectra. The rate of the data itself depends only on the number of comparative spectra

  and the scanning frequency of the image points. He is inde-

  during the number of spectral channels. The greater the number of spectral channels, the greater the security with which the measured data can be associated with a spectrum

  determined, subject to a constant data rate.

  It should be emphasized in particular that flexiblli-

  the system which, with a simple modification of the contents of the memory, can adapt very quickly to new tasks. Thus, for example, in the case of general use, the surface of the colored triangle can be divided into a certain number

  partial surfaces whose corresponding spectra are memorized.

  respondents. As already mentioned, for a special use only the spectra of particular objects, for example certain types of plants or stones, are memorized. For the use of the system in terrestrial observation satellites as well as in other stations it is possible, from a ground station, to change in a few seconds the contents of the memory and consequently to adapt the system JeaeJT; uapT e ja qo ,. eluemido uobe $ ap sefdfep eJre sPlinoTjjlp sues: uaAnad aovads enbteqo inod seaznaeldnts a3 seaJneTapjuT saTlu sinaGIA sap aouevsip el ap Jnan2uoi ee suoTssTw saeinep ç 00866tZ

Claims (5)

  A method for the compression and pre-processing of multispectral data to be transmitted from satellites or other stations, characterized in that the digital output data of the multispectral system is compared to many numbered spectra and stored on board satellite or station and only transmit the spectrum number corresponding to the data Release.   2. Method according to claim 1, characterized in that the comparative spectra are defined by lower and upper limit intensity values in each spectral channel and that the correspondence between one of the stored spectra and the measured data when these measured data in all the spectral channels are within the respective limit values   lower and upper parts of the spectrum.   3. Device for carrying out the method according to claim 1 or 2, characterized in that the data put into digital form of the different spectral channels is applied to the respective address lines (R) of a memory ( M) to N parallel data outputs, the outputs (Q1 - QN) being associated with the N different comparative spectra and that in a consecutive coincidence circuit (P1 - PN) it is determined whether in all the spectral channels   (1 - k) es Intensities of the measured data are at the same time   for a given spectrum between the lower and upper limit values and that in a binary encoder (BE)   downstream one converts the number of this signal colncl-   dence to a corresponding binary value.   4. Disposltif according to any of the claims   preceding cells, characterized in that the storage is performed in the memories (M), that for each spectral channel (1 - k) a memory of the quantity (2R x N bits) is used, R being the length of the bit of words of the measured data and R lines of address (A1-AR) and N lines of data output (Q1-Qn) being associated with each memory and that each of the N columns of the matrices of the memory can be 249MBOO associated with a spectrum. -   5. Device according to any one of the   previous cations, characterized by32 makes that one uses   wired or output memories that are operated the device in multiplexing.