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cropData

Crop regions-of-interest

    Description

    newhcube = cropData(hcube,row,column) crops the regions of interest (ROIs), specified by row and column, across all the spectral bands in the hyperspectral data cube hcube. The function returns the cropped data as a new hypercube object newhcube.

    example

    newhcube = cropData(hcube,row,column,band) crops the ROIs across the specified spectral bands band.

    Note

    This function requires the Image Processing Toolbox™ Hyperspectral Imaging Library. You can install the Image Processing Toolbox Hyperspectral Imaging Library from Add-On Explorer. For more information about installing add-ons, see Get and Manage Add-Ons.

    Examples

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    Read hyperspectral data from an ENVI format file.

    hcube = hypercube('paviaU.dat');

    Crop the first 10 spectral bands of the input data cube.

    newhcube = cropData(hcube,':',':',1:10);

    Specify the row and column indices of the ROI to crop from the extracted bands.

    row = 130:250;
    column = 60:200;

    Crop the ROI.

    newhcube = cropData(newhcube,row,column,':');

    Display both bands in the original and the cropped versions of a spectral band.

    fig = figure('Position',[0 0 800 500]);
    axes1 = axes('Parent',fig,'Position',[0.05 0.05 0.45 0.8]);
    imagesc(hcube.DataCube(:,:,5),'Parent',axes1)
    title('Original Data')
    axes2 = axes('Parent',fig,'Position',[0.55 0.05 0.45 0.8]);
    imagesc(newhcube.DataCube(:,:,5),'Parent',axes2)
    title('Cropped Data')   
    colormap gray

    Input Arguments

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    Input hyperspectral data, specified as a hypercube object. The DataCube property of the hypercube object contains the hyperspectral data cube.

    Row indices of the data cube, specified as ':', a positive integer, or a vector of positive integers.

    • To select all the rows in the data cube, use ':'.

    • To select a particular row or rows, specify the row index as a positive integer or vector of positive integers respectively. If the data cube is of size M-by-N-by-C, the specified row index values must all be less than or equal to M. To specify a range of row indices, or indices at a regular interval, use the colon operator. For example, row = 1:10.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

    Column indices of the data cube, specified as ':', a positive integer, or a vector of positive integers.

    • To select all the columns in the data cube, use ':'.

    • To select a particular column or columns, specify the column index as a positive integer or vector of positive integers respectively. If the data cube is of size M-by-N-by-C, the specified column index values must all be less than or equal to N. To specify a range of column indices, or indices at a regular interval, use the colon operator. For example, column = 1:10.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

    Spectral band numbers, specified as ':', a positive integer or a vector of positive integers.

    • To select all the bands in the data cube, use ':'.

    • To select a particular band or bands, specify the band number as a positive integer or vector of positive integers respectively. If the data cube is of size M-by-N-by-C, the specified band number values must all be less than or equal to C. To specify a range of band numbers or numbers at a regular interval, use the colon operator. For example, band = 1:10.

    Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | char | string

    Output Arguments

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    Output hyperspectral data, returned as a hypercube object.

    Introduced in R2020a