2.6. empix.crop

crop(input_signal, optional_params=None)

Crop a given input 2D hyperspy signal.

This Python function applies a series of optional transformations to a given input 2D hyperspy signal. Let us denote the input 2D hyperspy signal by \(F_{\mathbf{m}; l_x, l_y}\), where \(l_x\) and \(l_y\) are integers indexing the sampled horizontal and vertical coordinates respectively in the signal space of the input signal, and \(\mathbf{m}\) is a vector of integers representing the navigation indices of the input signal. The Python function effectively does the following:

1. Copies the input signal and optionally pads the copy along the horizontal and vertical axes in signal space according to the parameter pad_mode;

2. Constructs a cropping window in the signal space of the (optionally padded) copy of the input signal, with the cropping window dimensions being determined by the parameter window_dims;

3. Shifts the center of the cropping window to coordinates determined by the parameter center;

4. Shifts the center of the cropping window again to the coordinates of the pixel closest to the aforementioned coordinates in the previous step;

5. Crops the (optionally padded) copy of the input signal along the horizontal and vertical dimensions of the signal space according to the placement of the cropping window in the previous two steps;

6. Optionally applies a symmetric mask to the cropped signal resulting from the previous step according to the parameter apply_symmetric_mask.

See the description below of the optional parameters for more details.

Parameters:

input_signalhyperspy._signals.signal2d.Signal2D | hyperspy._signals.complex_signal2d.ComplexSignal2D

The input hyperspy signal.

optional_paramsempix.OptionalCroppingParams | None, optional

The set of optional parameters. See the documentation for the class empix.OptionalCroppingParams for details. If optional_params is set to None, rather than an instance of empix.OptionalCroppingParams, then the default values of the optional parameters are chosen.

Returns:

output_signalhyperspy._signals.signal2d.Signal2D | hyperspy._signals.complex_signal2d.ComplexSignal2D

The output hyperspy signal that results from the applied transformations, described above. Note that the metadata of the input signal is copied over to the output signal, with the title being overwritten.