acldvppNormalize

Applicability

Function

• Description: normalizes images by subtracting the mean value and then dividing the result by the standard deviation. The mean value and standard deviation are specified by users.
• Formula:

  out = (self - mean) / std

Prototype

Each operator has two-phase API calls. First, acldvppNormalizeGetWorkspaceSize is called to calculate the required workspace size based on the computation process. Then, acldvppNormalize is called to perform computation. The two-phase APIs are as follows:

• First-phase API:

  1	acldvppStatus acldvppNormalizeGetWorkspaceSize(const aclTensor* self, const aclFloatArray* mean, const aclFloatArray* std, aclTensor* out, uint64_t* workspaceSize, aclOpExecutor** executor)

• Second-phase API:

  1	acldvppStatus acldvppNormalize(void* workspace, uint64_t workspaceSize, aclOpExecutor* executor, aclrtStream stream)

acldvppNormalizeGetWorkspaceSize

• Parameters:
  • self: input tensor of the operator. Call aclCreateTensor to create data of the aclTensor type (stored on the device). The data type of the input tensor can be UINT8 or FLOAT, and the format can be NCHW or NHWC. Discontinuous tensors are not supported, in addition, N can be 1 or empty, and C can be 1 or 3. (1 indicates that the input data is in GRAY format, and 3 indicates that the input data is in the sequence of R, G, and B.)
  • mean: mean data. Call aclCreateFloatArray to create data of the aclFloatArray type (data is stored on the host side, and dataType is FLOAT). The size of the input parameter of this API must be the same as that of the C axis.
  • std: standard deviation data. Call aclCreateFloatArray to create data of the aclFloatArray type (data is stored on the host, and dataType is FLOAT). The size of the input parameter of this API must be the same as that of the C axis.
  • out: output tensor of the operator. Call aclCreateTensor to create data of the aclTensor type (stored on the device). The data type of the output tensor can be FLOAT, and non-contiguous tensors are not supported. The format and shape must be the same as those of self.
  • workspaceSize: size of the workspace to be allocated on the device.
  • executor: operator executor, containing the operator computation process.
• Returns:

  The status code acldvppStatus is returned. For details, see acldvpp Return Codes.

acldvppNormalize

• Parameters:
  • workspace: The aclrtMalloc API needs to be called to allocate the device memory. The memory size is workspaceSize. The memory address output by the aclrtMalloc API is passed here.
  • workspaceSize: The value must be the same as that obtained by calling acldvppNormalizeGetWorkspaceSize.
  • executor: op executor, which contains the operator computation process and is the same as the executor of the acldvppNormalizeGetWorkspaceSize API.
  • stream: stream for executing the task. You can reuse the created stream to save resources or call aclrtCreateStream to create a stream, and then pass the stream as an input parameter.
• Returns

  The status code acldvppStatus is returned. For details, see acldvpp Return Codes.

Constraints

The supported image resolution ranges from 6 x 4 to 4096 x 8192.