nvidia.dali.fn.warp_affine¶
-
nvidia.dali.fn.
warp_affine
(*inputs, **kwargs)¶ Applies an affine transformation to the images.
This operator supports volumetric data.
- Supported backends
‘cpu’
‘gpu’
- Parameters
input0 (TensorList ('HWC', 'FHWC', 'DHWC', 'FDHWC')) – Input to the operator.
input1 (TensorList, optional) – Input to the operator.
- Keyword Arguments
bytes_per_sample_hint (int or list of int, optional, default = [0]) –
Output size hint, in bytes per sample.
If specified, the operator’s outputs residing in GPU or page-locked host memory will be preallocated to accommodate a batch of samples of this size.
dtype (
nvidia.dali.types.DALIDataType
, optional) –Output data type.
If not set, the input type is used.
fill_value (float, optional) –
Value used to fill areas that are outside the source image.
If a value is not specified, the source coordinates are clamped and the border pixel is repeated.
interp_type (
nvidia.dali.types.DALIInterpType
, optional, default = DALIInterpType.INTERP_LINEAR) – Type of interpolation used.inverse_map (bool, optional, default = True) – Set to
False
if the given transform is a destination to source mapping,True
otherwise.matrix (float or list of float or TensorList of float, optional, default = []) –
Transform matrix.
When the
inverse_map
option is set to true (default), the matrix represents a destination to source mapping. With a list of values(M11, M12, M13, M21, M22, M23)
, this operation produces a new image by using the following formula:dst(x,y) = src(M11 * x + M12 * y + M13, M21 * x + M22 * y + M23)
Where
[0, 0]
coordinate means the corner of the first pixel.If the
inverse_map
option is set to false, the matrix represents a source to destination transform and it is inverted before applying the formula above.It is equivalent to OpenCV’s
warpAffine
operation with theinverse_map
argument being analog to theWARP_INVERSE_MAP
flag.Supports
per-frame
inputs.preserve (bool, optional, default = False) – Prevents the operator from being removed from the graph even if its outputs are not used.
seed (int, optional, default = -1) –
Random seed.
If not provided, it will be populated based on the global seed of the pipeline.
size (float or list of float or TensorList of float, optional, default = []) –
Output size, in pixels/points.
Non-integer sizes are rounded to nearest integer. The channel dimension should be excluded (for example, for RGB images, specify
(480,640)
, not(480,640,3)
.output_dtype (
nvidia.dali.types.DALIDataType
) –Warning
The argument
output_dtype
is a deprecated alias fordtype
. Usedtype
instead.