Data files

Access data file shipped with the Toolbox.

machinevisiontoolbox.base.data.mvtb_load_matfile(filename)[source]

Load toolbox mat format data file

Parameters:: filename (str) – relative pathname of datafile
Raises:: ValueError – File does not exist
Returns:: contents of mat data file
Return type:: dict

Reads a MATLAB format mat file which can contain multiple variables, in a binary or ASCII format. Returns a dict where the keys are the variable names and the values are NumPy arrays.

Note

Uses SciPy io.loadmat to do the work.
If the filename has no path component it will be first be looked for in the folder machinevisiontoolbox/data, then the current working directory.

Seealso:: mvtb_path_to_datafile scipy.io.loadmat

machinevisiontoolbox.base.data.mvtb_load_jsonfile(filename)[source]

Load toolbox JSON format data file

Parameters:: filename (str) – relative pathname of datafile
Raises:: ValueError – File does not exist
Returns:: contents of JSON data file
Return type:: dict

Reads a JSON format file which can contain multiple variables and return a dict where the keys are the variable names and the values are Python data types.

Note

If the filename has no path component it will be first be looked for in the folder machinevisiontoolbox/data, then the current working directory.

Seealso:: mvtb_path_to_datafile

machinevisiontoolbox.base.data.mvtb_load_data(filename, handler, **kwargs)[source]

Load toolbox data file

Parameters:

filename (str) – relative pathname of datafile
handler (callable) – function to read data

Raises:

ValueError – File does not exist

Returns:

data object

Resolves the relative pathname to an absolute name and then invokes the data reading function:

handler(abs_file_name, **kwargs)

For example:

data = mvtb_load_data('data/foo.dat', lambda f: data_load(open(f, 'r')))

Note

If the filename has no path component it will first be looked for in the folder machinevisiontoolbox/data, then the current working directory.

Seealso:: mvtb_path_to_datafile

machinevisiontoolbox.base.data.mvtb_path_to_datafile(*filename, local=True, string=False)[source]

Get absolute path to file in MVTB data package

Parameters:

filename (str) – pathname of image file
local (bool) – search for file locally first, default True

Raises:

FileNotFoundError – File does not exist

Returns:

Absolute path

Return type:

Path

The data associated with the Machine Vision Toolbox for Python is shipped as a separate package.

The positional arguments are joined, like os.path.join, for example:

mvtb_path_to_datafile('data', 'solar.dat')  # data/solar.dat

If local is True then ~ is expanded and if the file exists, the path is made absolute, and symlinks resolved:

mvtb_path_to_datafile('foo.dat')         # find ./foo.dat
mvtb_path_to_datafile('~/foo.dat')       # find $HOME/foo.dat

Otherwise, the file is sought within the mvtbdata package and if found, return that absolute path.

Example:

>>> from machinevisiontoolbox import mvtb_path_to_datafile
>>> mvtb_path_to_datafile('data', 'solar.dat')   # read mvtbdata/data/solar.dat
PosixPath('/opt/hostedtoolcache/Python/3.9.16/x64/lib/python3.9/site-packages/mvtbdata/data/solar.dat')