slmsuite.holography.toolbox.imprint#

imprint(matrix, window, function, grid=None, imprint_operation='replace', centered=False, circular=False, clip=True, transform=0, shift=(0, 0), **kwargs)[source]#

Imprints a region (defined by window) of a matrix with a function. This function must be in the style of phase phase helper functions, which expect a grid parameter to define the coordinate basis (see blaze() or lens()).

For instance, we can imprint a blaze on a 200 by 200 pixel region of the SLM with:

canvas = np.zeros(shape=slm.shape)  # Matrix to imprint onto.
window = [200, 200, 200, 200]       # Region of the matrix to imprint [x, w, y, h].
toolbox.imprint(canvas, window=window, function=toolbox.phase.blaze, grid=slm, vector=(.001, .001))

See also Examples.

Parameters:

  • matrix (numpy.ndarray) – The data to imprint a function onto.

  • window – Passed to window_slice(). See window_slice() for various options.

  • function (function OR float) –

    A function in the style of toolbox helper functions, which accept grid as the first argument.

    Note

    2D functions in fitfunctions are also of this style.

    Note

    Also accepts floating point values, in which case the value is simply added.

  • grid ((array_like, array_like) OR SLM OR None) – Meshgrids of normalized \(\frac{x}{\lambda}\) coordinates corresponding to SLM pixels, in (x_grid, y_grid) form. These are precalculated and stored in any SLM, so such a class can be passed instead of the grids directly if a toolbox function is used. None can only be passed if a float is passed as function.

  • imprint_operation ({"replace" OR "add"}) –

    Decides how the function is imparted to the matrix.

    • If "replace", then the values of matrix inside window are replaced with function.

    • If "add", then these are instead added together (useful, for instance, for adding global blazes).

  • centered – See window_slice().

  • circular – See window_slice().

  • clip (bool) – Whether to clip the imprint region if it exceeds the size of matrix. If False, then an error is raised when the size is exceeded. If True, then the out-of-range pixels are instead filled with numpy.nan.

  • transform (float or ((float, float), (float, float))) – Passed to transform_grid(), operating on the cropped imprint grid. This is left as an option such that the user does not have to transform the entire grid to satisfy a tiny imprinted patch. See transform_grid() for more details.

  • shift ((float, float) OR None OR True) – Passed to transform_grid(), operating on the cropped imprint grid. This is left as an option such that the user does not have to transform the entire grid to satisfy a tiny imprinted patch. If True, the grid is centered on the region. See transform_grid() for more details.

  • **kwargs – For passing additional arguments accepted by function.

Returns:

matrix – The modified image. Note that the matrix is modified in place, and this return is merely a copy of the user’s pointer to the data.

Return type:

numpy.ndarray

Raises:

ValueError – If invalid window or imprint_operation are provided.

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