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  <xs:element id="obnk_OwnerOccupiedCommercialRealEstateMember" abstract="true" name="OwnerOccupiedCommercialRealEstateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_LoansAndLeasesReceivableImpairedInterestOnNonaccrualLoans" abstract="false" name="LoansAndLeasesReceivableImpairedInterestOnNonaccrualLoans" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_ClassifiedMember" abstract="true" name="ClassifiedMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FinancingReceivableExcludingLoansAtFairValueBeforeAllowanceforCreditLoss" abstract="false" name="FinancingReceivableExcludingLoansAtFairValueBeforeAllowanceforCreditLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FinancingReceivableExcludingAccruedInterest3089DaysPastDueStillAccruing" abstract="false" name="FinancingReceivableExcludingAccruedInterest3089DaysPastDueStillAccruing" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_CreditLossExpenseReversal" abstract="false" name="CreditLossExpenseReversal" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_OtherMember" abstract="true" name="OtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FinancingAsset30To89DaysPastDueMember" abstract="true" name="FinancingAsset30To89DaysPastDueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FinancingReceivableExcludingAccruedInterestModifiedDefaultAmount" abstract="false" name="FinancingReceivableExcludingAccruedInterestModifiedDefaultAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_DebtSecuritiesFVNIMember" abstract="true" name="DebtSecuritiesFVNIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_RabbiTrustAssetsMember" abstract="true" name="RabbiTrustAssetsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FairValueOptionAggregateFairValue" abstract="false" name="FairValueOptionAggregateFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FairValueOptionAggregateUnpaidPrincipalBalance" abstract="false" name="FairValueOptionAggregateUnpaidPrincipalBalance" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_DeferredCompensationLiabilitiesRelatedToRabbiTrustAssetsMember" abstract="true" name="DeferredCompensationLiabilitiesRelatedToRabbiTrustAssetsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_ResidentialRealEstateLoanMember" abstract="true" name="ResidentialRealEstateLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_DebtSecuritiesFVNIMeasurementInput" abstract="false" name="DebtSecuritiesFVNIMeasurementInput" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_OtherInvestmentsFairValue" abstract="false" name="OtherInvestmentsFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_AccruedInterestReceivableFairValue" abstract="false" name="AccruedInterestReceivableFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_LoansandLeasesReceivableNetofDeferredIncomeFairValueDisclosure" abstract="false" name="LoansandLeasesReceivableNetofDeferredIncomeFairValueDisclosure" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FederalHomeLoanBankAdvancesandSecuritiesSoldUnderAgreementstoRepurchaseFairValue" abstract="false" name="FederalHomeLoanBankAdvancesandSecuritiesSoldUnderAgreementstoRepurchaseFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_JuniorSubordinatedDebentureOwedtoUnconsolidatedSubsidiaryTrustFairValue" abstract="false" name="JuniorSubordinatedDebentureOwedtoUnconsolidatedSubsidiaryTrustFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_A3.85FHLBAdvanceMember" abstract="true" name="A3.85FHLBAdvanceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_LoanAgreementMember" abstract="true" name="LoanAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_DebtInstrumentInterestRateFloor" abstract="false" name="DebtInstrumentInterestRateFloor" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_RiskParticipationDerivativeMember" abstract="true" name="RiskParticipationDerivativeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FinancialInstitutionMember" abstract="true" name="FinancialInstitutionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_CustomerMember" abstract="true" name="CustomerMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_DerivativeWeightedAverageInterestRate" abstract="false" name="DerivativeWeightedAverageInterestRate" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_A2012PlanAndTheOmnibusPlanMember" abstract="true" name="A2012PlanAndTheOmnibusPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_OmnibusPlanMember" abstract="true" name="OmnibusPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_A2012PlanMember" abstract="true" name="A2012PlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_AmendedPlanMember" abstract="true" name="AmendedPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_BTHMember" abstract="true" name="BTHMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardTargetPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardAmount" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonCompetitionCovenantTerm" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNonCompetitionCovenantTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallments" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallments" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfStockPriceHurdles" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfStockPriceHurdles" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformancePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardPriceAppreciation.Percentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPriceAppreciation.Percentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAverageClosingPricePeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAverageClosingPricePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardAppreciationRequirementPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAppreciationRequirementPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfConsecutiveTradingDays" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfConsecutiveTradingDays" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTranches" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTranches" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfCategories" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfCategories" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesConverted" abstract="false" name="BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesConverted" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="obnk_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsDividendYield" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsDividendYield" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_RestrictedStockAndRestrictedStockUnitsMember" abstract="true" name="RestrictedStockAndRestrictedStockUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_OriginBankMember" abstract="true" name="OriginBankMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_CommonEquityTierOneCapitalRequiredForCapitalAdequacyToRiskWeightedAssets" abstract="false" name="CommonEquityTierOneCapitalRequiredForCapitalAdequacyToRiskWeightedAssets" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="obnk_CommonEquityTierOneCapitalRequiredtobeWellCapitalizedtoRiskWeightedAssets" abstract="false" name="CommonEquityTierOneCapitalRequiredtobeWellCapitalizedtoRiskWeightedAssets" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="obnk_TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer" abstract="false" name="TierOneRiskBasedCapitalRequiredForCapitalAdequacyWithBuffer" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsWithBuffer" abstract="false" name="TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssetsWithBuffer" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="obnk_CapitalAndRegulatoryMattersTable" abstract="true" name="CapitalAndRegulatoryMattersTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="obnk_CapitalAndRegulatoryMattersLineItems" abstract="true" name="CapitalAndRegulatoryMattersLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="obnk_ShareRepurchaseProgramIncreaseInAuthorizedAmount" abstract="false" name="ShareRepurchaseProgramIncreaseInAuthorizedAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_CommitmentsToExtendCreditUnconditionalCancellableCommitmentsMember" abstract="true" name="CommitmentsToExtendCreditUnconditionalCancellableCommitmentsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_FairValueDisclosureOffBalanceSheetRisksAmountLiabilityLessThanOneYear" abstract="false" name="FairValueDisclosureOffBalanceSheetRisksAmountLiabilityLessThanOneYear" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FairValueDisclosureOffBalanceSheetRisksAmountLiabilityOneYearThroughThreeYears" abstract="false" name="FairValueDisclosureOffBalanceSheetRisksAmountLiabilityOneYearThroughThreeYears" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FairValueDisclosureOffBalanceSheetRisksAmountLiabilityThreeYearsThroughFiveYears" abstract="false" name="FairValueDisclosureOffBalanceSheetRisksAmountLiabilityThreeYearsThroughFiveYears" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FairValueDisclosureOffBalanceSheetRisksAmountLiabilityGreaterThanFiveYears" abstract="false" name="FairValueDisclosureOffBalanceSheetRisksAmountLiabilityGreaterThanFiveYears" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="obnk_FederalHomeLoanBankMember" abstract="true" name="FederalHomeLoanBankMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_LossContingencyLoansMember" abstract="true" name="LossContingencyLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="obnk_LineOfCreditFacilityNumberOfInstruments" abstract="false" name="LineOfCreditFacilityNumberOfInstruments" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="obnk_ReserveforLendingRelatedCommitments" abstract="false" name="ReserveforLendingRelatedCommitments" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
