PIBIO_ENGINE_IDENTIFY_FEATURE_SET_FN回调函数 (winbio_adapter.h)
由 Windows 生物识别框架调用，以从当前功能集生成模板并在数据库中查找匹配的模板。 如果可以找到匹配项，则引擎适配器必须使用存储的模板中的相应信息填充 Identity、 SubFactor、 PayloadBlob 参数。
语法
PIBIO_ENGINE_IDENTIFY_FEATURE_SET_FN PibioEngineIdentifyFeatureSetFn;
HRESULT PibioEngineIdentifyFeatureSetFn(
[in, out] PWINBIO_PIPELINE Pipeline,
[out] PWINBIO_IDENTITY Identity,
[out] PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
[out] PUCHAR *PayloadBlob,
[out] PSIZE_T PayloadBlobSize,
[out] PUCHAR *HashValue,
[out] PSIZE_T HashSize,
[out] PWINBIO_REJECT_DETAIL RejectDetail
)
{...}
参数
[in, out] Pipeline
指向与执行操作的生物识别单元关联的 WINBIO_PIPELINE 结构的指针。
[out] Identity
指向 WINBIO_IDENTITY 结构的指针，该结构包含从数据库恢复的模板的 GUID 或 SID。 仅当找到匹配项时，才会返回此值。
[out] SubFactor
一个WINBIO_BIOMETRIC_SUBTYPE值，用于接收与数据库中的模板关联的子因子。 有关更多详细信息，请参阅“备注”部分。 仅当找到匹配项时，才会返回此值。
[out] PayloadBlob
变量的地址，该变量接收指向与模板一起保存的有效负载数据的指针。 如果没有有效负载数据，请将此值设置为 NULL。
[out] PayloadBlobSize
指向一个变量的指针，该变量接收 由 PayloadBlob 参数指定的缓冲区的大小（以字节为单位）。 如果没有有效负载数据，请将此值设置为零。
[out] HashValue
一个变量的地址，该变量接收指向模板生成的哈希值的指针。 如果引擎适配器不支持哈希生成，请将此值设置为 NULL。
[out] HashSize
指向一个变量的指针，该变量接收 HashValue 参数指定的缓冲区的大小（以字节为单位）。 如果引擎适配器不支持哈希生成，请将此值设置为零。
[out] RejectDetail
指向变量的指针，该变量在捕获失败导致引擎无法执行匹配操作时接收其他信息。 如果最近的捕获成功，请将此参数设置为零。 为指纹捕获定义了以下值：
- WINBIO_FP_TOO_HIGH
- WINBIO_FP_TOO_LOW
- WINBIO_FP_TOO_LEFT
- WINBIO_FP_TOO_RIGHT
- WINBIO_FP_TOO_FAST
- WINBIO_FP_TOO_SLOW
- WINBIO_FP_POOR_QUALITY
- WINBIO_FP_TOO_SKEWED
- WINBIO_FP_TOO_SHORT
- WINBIO_FP_MERGE_FAILURE
返回值
如果函数成功，它将返回S_OK以指示上次更新成功，并且无需其他功能集即可完成模板。 如果函数失败，它必须返回以下 HRESULT 值之一来指示错误。
| 返回代码 | 说明 |
|---|---|
|
Pipeline 参数为 NULL。 |
|
功能集未满足引擎适配器对标识操作的内部要求。 有关失败的详细信息由 RejectDetail 参数指定。 |
|
管道中的功能集不对应于数据库中的任何标识。 |
注解
用于生成模板哈希的算法是此管道上最近调用 EngineAdapterSetHashAlgorithm 时选择的算法。
此函数返回的哈希值（如果有）是在数据库中找到的注册模板的哈希值，而不是附加到管道的匹配模板。
EngineAdapterIdentifyFeatureSet 函数成功返回后，PayloadBlob 和 HashValue 缓冲区由引擎适配器拥有和管理。 对于此管道，引擎适配器必须保持缓冲区地址有效，直到下一次调用 EngineAdapterClearContext。
示例
以下伪代码演示了此函数的一种可能实现。 该示例不编译。 必须根据自己的目的调整它。
//////////////////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterIdentifyFeatureSet
//
// Purpose:
// Build a template from the current feature set and locate a matching
// template in the database.
//
// Parameters:
// Pipeline - Pointer to a WINBIO_PIPELINE structure associated
// with the biometric unit performing the operation
// Identity - The GUID or SID of the template recovered from the
// database
// SubFactor - Sub-factor associated with the template in the
// database
// PayloadBlob - Payload data saved with the template
// PayloadBlobSize - Size, in bytes, of the buffer specified by the
// PayloadBlob parameter.
// HashValue - Hash value for the template
// HashSize - Size, in bytes, of the buffer specified by the
// HashValue parameter.
// RejectDetail - Receives additional information if a capture
// failure prevents the engine from performing a matching
// operation.
//
static HRESULT
WINAPI
EngineAdapterIdentifyFeatureSet(
__inout PWINBIO_PIPELINE Pipeline,
__out PWINBIO_IDENTITY Identity,
__out PWINBIO_BIOMETRIC_SUBTYPE SubFactor,
__out PUCHAR *PayloadBlob,
__out PSIZE_T PayloadBlobSize,
__out PUCHAR *HashValue,
__out PSIZE_T HashSize,
__out PWINBIO_REJECT_DETAIL RejectDetail
)
{
HRESULT hr = S_OK;
SIZE_T recordCount = 0;
SIZE_T index = 0;
WINBIO_STORAGE_RECORD thisRecord;
BOOLEAN match = FALSE;
DWORD indexVector[NUMBER_OF_TEMPLATE_BINS] = {0};
// Verify that pointer arguments are not NULL.
if (!ARGUMENT_PRESENT(Pipeline) ||
!ARGUMENT_PRESENT(Identity) ||
!ARGUMENT_PRESENT(SubFactor) ||
!ARGUMENT_PRESENT(PayloadBlob) ||
!ARGUMENT_PRESENT(PayloadBlobSize) ||
!ARGUMENT_PRESENT(HashValue) ||
!ARGUMENT_PRESENT(HashSize) ||
!ARGUMENT_PRESENT(RejectDetail))
{
hr = E_POINTER;
goto cleanup;
}
// Retrieve the context from the pipeline.
PWINBIO_ENGINE_CONTEXT context =
(PWINBIO_ENGINE_CONTEXT)Pipeline->EngineContext;
// Initialize the return values.
ZeroMemory( Identity, sizeof(WINBIO_IDENTITY));
Identity->Type = WINBIO_ID_TYPE_NULL;
*SubFactor = WINBIO_SUBTYPE_NO_INFORMATION;
*PayloadBlob = NULL;
*PayloadBlobSize = 0;
*HashValue = NULL;
*HashSize = 0;
*RejectDetail = 0;
// The biometric unit cannot perform verification or identification
// operations while it is performing an enrollment sequence.
if (context->Enrollment.InProgress == TRUE)
{
hr = WINBIO_E_ENROLLMENT_IN_PROGRESS;
goto cleanup;
}
// If your adapter supports index vectors to place templates into buckets,
// call a custom function (_AdapterCreateIndexVector) to create an index
// vector from the template data in the feature set. In this example, the
// engine adapter context attached to the pipeline contains a FeatureSet
// member.
hr = _AdapterCreateIndexVector(
context,
context->FeatureSet,
context->FeatureSetSize,
indexVector,
NUMBER_OF_TEMPLATE_BINS,
RejectDetail
);
if (FAILED(hr))
{
goto cleanup;
}
// Retrieve the records in the index vector. If your adapter does not support
// index vectors (the vector length is zero), calling the WbioStorageQueryByContent
// function will retrieve all records.
// WbioStorageQueryByContent is a wrapper function in the Winbio_adapter.h
// header file.
hr = WbioStorageQueryByContent(
Pipeline,
WINBIO_SUBTYPE_ANY,
indexVector,
NUMBER_OF_TEMPLATE_BINS
);
if (FAILED(hr))
{
goto cleanup;
}
// Determine the size of the result set. WbioStorageGetRecordCount is a wrapper
// function in the Winbio_adapter.h header file.
hr = WbioStorageGetRecordCount( Pipeline, &recordCount);
if (FAILED(hr))
{
goto cleanup;
}
// Point the result set cursor at the first record. WbioStorageFirstRecord
// is a wrapper function in the Winbio_adapter.h header file.
hr = WbioStorageFirstRecord( Pipeline );
if (FAILED(hr))
{
goto cleanup;
}
// Iterate through all records in the result set and determine which record
// matches the current feature set. WbioStorageGetCurrentRecord is a wrapper
// function in the Winbio_adapter.h header file.
for (index = 0; index < recordCount; ++index)
{
hr = WbioStorageGetCurrentRecord( Pipeline, &thisRecord );
if (FAILED(hr))
{
goto cleanup;
}
// Call a custom function (_AdapterCompareTemplateToCurrentFeatureSet) to
// compare the feature set attached to the pipeline with the template
// retrieved from storage.
// If the template and feature set do not match, return WINBIO_E_NO_MATCH
// and set the Match parameter to FALSE.
// If your custom function cannot process the feature set, return
// WINBIO_E_BAD_CAPTURE and set extended error information in the
// RejectDetail parameter.
hr = _AdapterCompareTemplateToCurrentFeatureSet(
context,
context->FeatureSet,
context->FeatureSetSize,
thisRecord.TemplateBlob,
thisRecord.TemplateBlobSize,
&match,
RejectDetail
);
if (FAILED(hr) && hr != WINBIO_E_NO_MATCH)
{
goto cleanup;
}
if (match)
{
break;
}
hr = WbioStorageNextRecord( Pipeline );
if (FAILED(hr))
{
if (hr == WINBIO_E_DATABASE_NO_MORE_RECORDS)
{
hr = S_OK;
break;
}
else
{
goto cleanup;
}
}
}
if (match)
{
// If there is a match and if your engine adapter supports template
// hashing, call a custom function (_AdapterGenerateHashForTemplate)
// to calculate the hash. Save the hash value in the context area of
// the engine adapter.
// Skip this step if your adapter does not support template hashing.
hr = _AdapterGenerateHashForTemplate(
context,
thisRecord.TemplateBlob,
thisRecord.TemplateBlobSize,
context->HashBuffer,
&context->HashSize
);
if (FAILED(hr))
{
goto cleanup;
}
// Return information about the matching template to the caller.
CopyMemory( Identity, thisRecord.Identity, sizeof(WINBIO_IDENTITY));
*SubFactor = thisRecord.SubFactor;
*PayloadBlob = thisRecord.PayloadBlob;
*PayloadBlobSize = thisRecord.PayloadBlobSize;
*HashValue = &context->HashBuffer;
*HashSize = context->HashSize;
}
else
{
hr = WINBIO_E_UNKNOWN_ID;
}
cleanup:
if (hr == WINBIO_E_DATABASE_NO_RESULTS)
{
hr = WINBIO_E_UNKNOWN_ID;
}
return hr;
}
要求
| 最低受支持的客户端 | Windows 7 [仅限桌面应用] |
| 最低受支持的服务器 | Windows Server 2008 R2 [仅限桌面应用] |
| 目标平台 | Windows |
| 标头 | winbio_adapter.h (包括 Winbio_adapter.h) |