tf.raw_ops.UniformRequantize

Given quantized tensor input, requantize it with new quantization parameters.

tf.raw_ops.UniformRequantize(
    input,
    input_scales,
    input_zero_points,
    output_scales,
    output_zero_points,
    Tout,
    input_quantization_min_val,
    input_quantization_max_val,
    output_quantization_min_val,
    output_quantization_max_val,
    input_quantization_axis=-1,
    output_quantization_axis=-1,
    name=None
)

Given quantized tensor input, which was quantized using {input_scales, input_zero_points, input_quantization_axis, input_quantization_min_val, input_quantization_max_val}, requantize it to a tensor, which is quantized using {output_scales, output_zero_points, output_quantization_axis, output_quantization_min_val, output_quantization_max_val}. The requantization is done by using the formula: output_quantized_data = clip( (input_quantized_data - input_zero_point) * (input_scale / output_scale) + output_zero_point, output_quantization_min_val, output_quantization_max_val)

Per-tensor and per-axis quantization supported cases are followings:

  • per-tensor -> per-tensor
  • per-tensor -> per-axis
  • per-axis -> per-axis where input_quantization_axis equals output_quantization_axis. i.e. At least one among input_quantization_axis and output_quantization_axis must be -1, or two must be equal.

input A Tensor. Must be one of the following types: qint8, qint32. Must be a Tensor of Tin.
input_scales A Tensor of type float32. The float value(s) used as scale(s) when quantizing original data that input represents. Must be a scalar Tensor if quantization_axis is -1 (per-tensor quantization), otherwise 1D Tensor of size (input.dim_size(quantization_axis),) (per-axis quantization).
input_zero_points A Tensor of type int32. The int32 value(s) used as zero_point(s) when quantizing original data that input represents. Same shape condition as scales.
output_scales A Tensor of type float32. The float value(s) to use as new scale(s) to quantize original data that input represents. Must be a scalar Tensor if quantization_axis is -1 (per-tensor quantization), otherwise 1D Tensor of size (input.dim_size(quantization_axis),) (per-axis quantization).
output_zero_points A Tensor of type int32. The int32 value(s) to use as new zero_point(s) to quantize original data that input represents. Same shape condition as scales.
Tout A tf.DType from: tf.qint8, tf.qint32. The type of output Tensor. A tf.DType from: tf.qint8, tf.qint32
input_quantization_min_val An int. The quantization min value that was used when quantizing original data that input represents. The purpose of this attribute is typically (but not limited to) to indicate narrow range, where this is set to: (Tin lowest) + 1 if narrow range, and (Tin lowest) otherwise. For example, if Tin is qint8, this is set to -127 if narrow range quantized or -128 if not.
input_quantization_max_val An int. The quantization max value that was used when quantizing original data that input represents. The purpose of this attribute is typically (but not limited to) indicate narrow range, where this is set to: (Tout max) for both narrow range and not narrow range. For example, if Tin is qint8, this is set to 127.
output_quantization_min_val An int. The new quantization min value to quantize original data that input represents.
output_quantization_max_val An int. The new quantization max value to quantize original data that input represents.
input_quantization_axis An optional int. Defaults to -1. The quantization axis that was used when quantizing original data that input represents. Indicates the dimension index of the tensor where per-axis quantization is applied for the slices along that dimension. If set to -1 (default), this indicates per-tensor quantization. Otherwise, it must be set within range [0, input.dims()).
output_quantization_axis An optional int. Defaults to -1. The new quantization axis to use to quantize original data that input represents.
name A name for the operation (optional).

A Tensor of type Tout.