Error: array indices must be positive integers

Hello, I'm new here, I have a question. When I try to execute the attached code I get the error message: "Array indices must be positive integers or logical values. Error in Untitled233>g2l (line 12) B1=xxx(B)/5.4426; Error in Untitled233 (line 2) testv=g2l(cast(y1,'uint8'));"

It says that the array indices must be integers, but I use numbers from an uint8 image as the indices, so why does it say they are not integers? Besides that, the error seems to indicate that the first time the error is encoutered is in line 12 with 'B1=xxx(B)/5.4426', would that mean that only the values from B are not integers? Why wouldn't B consist of integers but would R and G?

Thanks in advance.

y1=imresize(webread('http://www.cs.albany.edu/~xypan/research/img/Kodak/kodim21.png'),[360,360]);
testv=g2l(cast(y1,'uint8'));

function outputluminance=g2l(grayinput)
zzz=[-0.0245800000000000	-0.0244955200000000	-0.0242097032878820	-0.0237010252078527	-0.0229568980231368	-0.0219680915258250	-0.0207272363214161	-0.0192281623989676	-0.0174655430224352	-0.0154346793888438	-0.0131313598444584	-0.0105517624996849	-0.00769238491066181	-0.00454999155923436	-0.00112157353868598	0.00259568309890936	0.00660442267160571	0.0109071404674750	0.0155061997345663	0.0204038458656814	0.0256022183690718	0.0311033610673987	0.0369092308614722	0.0430217053185676	0.0494425892885454	0.0561736207086544	0.0632164757257502	0.0705727732399610	0.0782440789546231	0.0862319090022280	0.0945377332041541	0.103162978012386	0.112109029173695	0.121377234150487	0.130968904327364	0.140885317028231	0.151127717365240	0.161697319937970	0.172595310398732	0.183822846897865	0.195381061421106	0.207271061029623	0.219493929012043	0.232050725956684	0.244942490751279	0.258170241516644	0.271734976480063	0.285637674793499	0.299879297301252	0.314460787261179	0.329383071023190	0.344647058668355	0.360253644611665	0.376203708171158	0.392498114105913	0.409137713125147	0.426123342370490	0.443455825873292	0.461135974988689	0.479164588807978	0.497542454550756	0.516270347938120	0.535349033548163	0.554779265154860	0.574561786051386	0.594697329358811	0.615186618321057	0.636030366586914	0.657229278479888	0.678784049256561	0.700695365354130	0.722963904627711	0.745590336577981	0.768575322569685	0.791919516041475	0.815623562707569	0.839688100751625	0.864113761013251	0.888901167167509	0.914050935897777	0.939563677062283	0.965439993854624	0.991680482958569	1.01828573469740	1.04525633317806	1.07259285643035	1.10029587654139	1.12836595978556	1.15680366675016	1.18560955245689	1.21478416647946	1.24432805305737	1.27424175120610	1.30452579482386	1.33518071279504	1.36620702909037	1.39760526286424	1.42937592854890	1.46151953594595	1.49403659031518	1.52692759246068	1.56019303881465	1.59383342151862	1.62784922850256	1.66224094356165	1.69700904643092	1.73215401285797	1.76767631467354	1.80357641986029	1.83985479261971	1.87651189343728	1.91354817914587	1.95096410298754	1.98876011467377	2.02693666044407	2.06549418312319	2.10443312217687	2.14375391376618	2.18345699080055	2.22354278298949	2.26401171689307	2.30486421597120	2.34610070063168	2.38772158827717	2.42972729335105	2.47211822738219	2.51489479902873	2.55805741412082	2.60160647570237	2.64554238407197	2.68986553682275	2.73457632888146	2.77967515254665	2.82516239752605	2.87103845097305	2.91730369752255	2.96395851932589	3.01100329608511	3.05843840508653	3.10626422123355	3.15448111707882	3.20308946285570	3.25208962650918	3.30148197372605	3.35126686796452	3.40144467048328	3.45201574036990	3.50298043456876	3.55433910790838	3.60609211312819	3.65823980090490	3.71078251987820	3.76372061667612	3.81705443593980	3.87078432034789	3.92491061064038	3.97943364564211	4.03435376228573	4.08967129563437	4.14538657890374	4.20149994348397	4.25801171896097	4.31492223313747	4.37223181205361	4.42994078000725	4.48804945957386	4.54655817162610	4.60546723535305	4.66477696827908	4.72448768628247	4.78459970361361	4.84511333291300	4.90602888522886	4.96734667003451	5.02906699524539	5.09119016723588	5.15371649085578	5.21664626944656	5.27997980485731	5.34371739746048	5.40785934616731	5.47240594844306	5.53735750032197	5.60271429642200	5.66847662995934	5.73464479276267	5.80121907528721	5.86819976662858	5.93558715453640	6.00338152542773	6.07158316440024	6.14019235524525	6.20920938046057	6.27863452126304	6.34846805760105	6.41871026816675	6.48936143040812	6.56042182054088	6.63189171356018	6.70377138325217	6.77606110220539	6.84876114182194	6.92187177232861	6.99539326278772	7.06932588110788	7.14366989405462	7.21842556726076	7.29359316523679	7.36917295138099	7.44516518798942	7.52157013626586	7.59838805633149	7.67561920723454	7.75326384695976	7.83132223243776	7.90979461955426	7.98868126315916	8.06798241707555	8.14769833410857	8.22782926605413	8.30837546370757	8.38933717687216	8.47071465436751	8.55250814403789	8.63471789276038	8.71734414645299	8.80038715008262	8.88384714767298	8.96772438231231	9.05201909616113	9.13673153045975	9.22186192553585	9.30741052081181	9.39337755481204	9.47976326517021	9.56656788863637	9.65379166108396	9.74143481751682	9.82949759207603	9.91798021804667	10.0068829278646	10.0962059531230	10.1859495245790	10.2761138721601	10.3666992249706	10.4577058112978	10.5491338586183	10.6409835936044	10.7332552421298	10.8259490292760	10.9190651793380	11.0126039158301	11.1065654614923	11.2009500382952	11.2957578674465	11.3909891693961];
yyy=[-0.0796829000000000	-0.0786317204654614	-0.0767488068841287	-0.0739824347315323	-0.0702944940828806	-0.0656544536738020	-0.0600366825408970	-0.0534190037233320	-0.0457818176021774	-0.0371075276319722	-0.0273801424216835	-0.0165849879801204	-0.00470849250723404	0.00826197899984288	0.0223382547491259	0.0375314602894821	0.0538521032835721	0.0713101434865733	0.0899150512188669	0.109675856749951	0.130601192403904	0.152699328764633	0.175978206045685	0.200445461458084	0.226108453236396	0.252974281851643	0.281049808838462	0.310341673585212	0.340856308373877	0.372599951907496	0.405578661523566	0.439798324260164	0.475264666915687	0.511983265222012	0.549959552233459	0.589198826019437	0.629706256736655	0.671486893146606	0.714545668635508	0.758887406786688	0.804516826549173	0.851438547041051	0.899657092021597	0.949176894062288	1.00000229844347	1.05213756680045	1.10558688054038	1.16035434404887	1.21644398770350	1.27385977070962	1.33260558377221	1.39268525161653	1.45410253536863	1.51686113480631	1.58096469048966	1.64641678577988	1.71322094875398	1.78138065402268	1.85089932445784	1.92178033283546	1.99402700339973	2.06764261335320	2.14263039427761	2.21899353348976	2.29673517533631	2.37585842243124	2.45636633683925	2.53826194120827	2.62154821985410	2.70622811979965	2.79230455177157	2.87978039115638	2.96865847891839	3.05894162248149	3.15063259657653	3.24373414405633	3.33824897667973	3.43417977586639	3.53152919342373	3.63029985224743	3.73049434699675	3.83211524474582	3.93516508561217	4.03964638336340	4.14556162600319	4.25291327633737	4.36170377252117	4.47193552858834	4.58361093496302	4.69673235895502	4.81130214523935	4.92732261632059	5.04479607298277	5.16372479472530	5.28411104018560	5.40595704754904	5.52926503494644	5.65403720083998	5.78027572439766	5.90798276585696	6.03716046687808	6.16781095088709	6.29993632340943	6.43353867239413	6.56862006852907	6.70518256554760	6.84322820052692	6.98275899417837	7.12377695113004	7.26628406020201	7.41028229467424	7.55577361254773	7.70275995679883	7.85124325562719	8.00122542269742	8.15270835737471	8.30569394495470	8.46018405688761	8.61618055099697	8.77368527169313	8.93270005018151	9.09322670466612	9.25526704054812	9.41882285061982	9.58389591525422	9.75048800259016	9.91860086871323	10.0882362578327	10.2593959024543	10.4320815235494	10.6062948307203	10.7820375223618	10.9593112858196	11.1381177975451	11.3184587232464	11.5003357180371	11.6837504265814	11.8687044832358	12.0551995121884	12.2432371275954	12.4328189337142	12.6239465250345	12.8166214864063	13.0108453931653	13.2066198112562	13.4039462973531	13.6028263989780	13.8032616546164	14.0052535938315	14.2088037373751	14.4139135972977	14.6205846770550	14.8288184716140	15.0386164675556	15.2499801431764	15.4629109685883	15.6774104058159	15.8934799088924	16.1111209239541	16.3303348893325	16.5511232356452	16.7734873858855	16.9974287555093	17.2229487525218	17.4500487775617	17.6787302239846	17.9089944779443	18.1408429184735	18.3742769175623	18.6092978402361	18.8459070446317	19.0841058820722	19.3238956971409	19.5652778277536	19.8082536052303	20.0528243543648	20.2989913934943	20.5467560345667	20.7961195832080	21.0470833387875	21.2996485944827	21.5538166373432	21.8095887483529	22.0669662024920	22.3259502687976	22.5865422104234	22.8487432846990	23.1125547431870	23.3779778317411	23.6450137905614	23.9136638542504	24.1839292518672	24.4558112069812	24.7293109377254	25.0044296568479	25.2811685717640	25.5595288846061	25.8395117922744	26.1211184864852	26.4043501538200	26.6892079757729	26.9756931287980	27.2638067843554	27.5535501089575	27.8449242642137	28.1379304068748	28.4325696888774	28.7288432573867	29.0267522548393	29.3262978189855	29.6274810829303	29.9303031751749	30.2347652196568	30.5408683357896	30.8486136385028	31.1580022382797	31.4690352411965	31.7817137489599	32.0960388589441	32.4120116642276	32.7296332536301	33.0489047117474	33.3698271189878	33.6924015516061	34.0166290817389	34.3425107774379	34.6700477027040	34.9992409175204	35.3300914778853	35.6626004358442	35.9967688395220	36.3325977331546	36.6700881571197	37.0092411479682	37.3500577384540	37.6925389575646	38.0366858305502	38.3824993789535	38.7299806206385	39.0791305698190	39.4299502370872	39.7824406294412	40.1366027503129	40.4924375995955	40.8499461736698	41.2091294654316	41.5699884643175	41.9325241563313	42.2967375240693	42.6626295467464	43.0302012002206	43.3994534570182	43.7703872863584	44.1430036541774	44.5173035231527	44.8932878527266];
xxx=[-0.0342534000000000	-0.0334578170665024	-0.0322881537738871	-0.0307818057192417	-0.0289625503336234	-0.0268475430399854	-0.0244500530781136	-0.0217808123228827	-0.0188487758506525	-0.0156615909940929	-0.0122259059142904	-0.00854758278827010	-0.00463185088111556	-0.000483419930091218	0.00389343368148974	0.00849480000000000	0.0133170825604131	0.0183569558355660	0.0236113305590749	0.0290773251180938	0.0347522416967607	0.0406335461882799	0.0467188511328477	0.0530059011115412	0.0594925601533037	0.0661768008068246	0.0730566946006336	0.0801304036694003	0.0873961733667188	0.0948523257176751	0.102497253590546	0.110329415487693	0.118347330872327	0.126549575961260	0.134934779924676	0.143501621442897	0.152248825577534	0.161175160920490	0.170279436989402	0.179560501842391	0.189017239888577	0.198648569873851	0.208453443024017	0.218430841329587	0.228579775958421	0.238899285784038	0.249388436018807	0.260046316942456	0.270872042717389	0.281864750283220	0.293023598323730	0.304347766300176	0.315836453545471	0.327488878414337	0.339304277484970	0.351281904808231	0.363421031200707	0.375720943578368	0.388180944327814	0.400800350712387	0.413578494310666	0.426514720485069	0.439608387878489	0.452858867937059	0.466265544457298	0.479827813156043	0.493545081261678	0.507416767125310	0.521442299850635	0.535621118941339	0.549952673964958	0.564436424232213	0.579071838490895	0.593858394633451	0.608795579417484	0.623882888198427	0.639119824673702	0.654505900637739	0.670040635747249	0.685723557296204	0.701554200000000	0.717532105788327	0.733656823606279	0.749927909223297	0.766344925049532	0.782907439959266	0.799615029121033	0.816467273834115	0.833463761371104	0.850604084826238	0.867887842969238	0.885314640104385	0.902884085934599	0.920595795430284	0.938449388702733	0.956444490881873	0.974580731998172	0.992857746868518	1.01127517498589	1.02983266041268	1.04852985167747	1.06736640167518	1.08634196757038	1.10545621070368	1.12470879650101	1.14409939438584	1.16362767769392	1.18329332359081	1.20309601299173	1.22303543048396	1.24311126425140	1.26332320600146	1.28367095089401	1.30415419747244	1.32477264759658	1.34552600637767	1.36641398211508	1.38743628623475	1.40859263322940	1.42988274060041	1.45130632880116	1.47286312118198	1.49455284393657	1.51637522604984	1.53832999924707	1.56041689794445	1.58263565920088	1.60498602267102	1.62746773055950	1.65008052757636	1.67282416089349	1.69569838010229	1.71870293717226	1.74183758641070	1.76510208442329	1.78849619007571	1.81201966445616	1.83567227083871	1.85945377464760	1.88336394342233	1.90740254678355	1.93156935639982	1.95586414595499	1.98028669111648	2.00483676950416	2.02951416065999	2.05431864601833	2.07925000887688	2.10430803436829	2.12949250943239	2.15480322278897	2.18023996491127	2.20580252799987	2.23149070595730	2.25730429436305	2.28324309044922	2.30930689307659	2.33549550271123	2.36180872140161	2.38824635275612	2.41480820192108	2.44149407555925	2.46830378182865	2.49523713036192	2.52229393224599	2.54947400000229	2.57677714756717	2.60420319027284	2.63175194482863	2.65942322930262	2.68721686310358	2.71513266696334	2.74317046291942	2.77133007429799	2.79961132569721	2.82801404297083	2.85653805321206	2.88518318473786	2.91394926707336	2.94283613093671	2.97184360822405	3.00097153199495	3.03021973645788	3.05958805695614	3.08907632995392	3.11868439302263	3.14841208482749	3.17825924511437	3.20822571469679	3.23831133544317	3.26851595026440	3.29883940310143	3.32928153891324	3.35984220366492	3.39052124431601	3.42131850880897	3.45223384605788	3.48326710593733	3.51441813927150	3.54568679782337	3.57707293428414	3.60857640226287	3.64019705627617	3.67193475173817	3.70378934495057	3.73576069309291	3.76784865421295	3.80005308721721	3.83237385186166	3.86481080874259	3.89736381928754	3.93003274574648	3.96281745118301	3.99571779946579	4.02873365526003	4.06186488401915	4.09511135197659	4.12847292613763	4.16194947427151	4.19554086490348	4.22924696730708	4.26306765149655	4.29700278821927	4.33105224894833	4.36521590587528	4.39949363190292	4.43388530063817	4.46839078638513	4.50300996413814	4.53774270957504	4.57258889905041	4.60754840958904	4.64262111887935	4.67780690526701	4.71310564774861	4.74851722596540	4.78404152019716	4.81967841135609	4.85542778098086	4.89128951123069	4.92726348487950	4.96334958531020	4.99954769650899	5.03585770305979	5.07227949013869	5.10881294350854	5.14545794951352	5.18221439507392	5.21908216768081	5.25606115539095	5.29315124682165	5.33035233114574	5.36766429808663	5.40508703791338	5.44262044143586	5.48026440000000];

[R,G,B]=imsplit(grayinput);
R1=zzz(R)/11.2958;
G1=yyy(G)/44.5173;
B1=xxx(B)/5.4426;
outputluminance=cat(3,R1,G1,B1);
end

Answer 1

[Jan]

You can use the debugger to find the cause of the problem. Let Matlab stop when the error occurs:

dbstop if error

Type this in the command window and run the code again. When it stops at the error, examine the value of the index:

unique(B)

The values can be integers, but not "positive integers", if they contain the value 0, which is not a valid index.

[LucasH]

Thank you very much, this was the problem indeed. I solved it by using B+1 instead of B.