Fix npy channel

[mrariden]

Changing the MainW.color from int to str caused loading/saving .npy files to fail when loading 'current_channel'. Added backwards-compatible check that allows old .npy files to be opened with new cellpose versions. In that case, the behavior is to set default 'current_channel' to RGB.

Also ensured GUI loads image with update_plot() when loading .npy file.

• GUI testing protocol
• GH tests
• Mac/ubuntu tests

[carsen-stringer]

Thanks Michael, so seg.npy files will still open the same exact way as before?

[mrariden]

use this script to fix intermediate _seg.npy files:

import click
import numpy as np
from pathlib import Path


@click.command()
@click.argument('filename')
def main(filename: str|Path):
    filename = Path(filename)

    file_data = np.load(filename, allow_pickle=True).item()
    color = file_data['current_channel']
    if isinstance(color, str):
        click.echo(f'found incorrect `color` type: ({str(color)}), changing to int')
        file_data['current_channel'] = 0
    else:
        click.echo('file seems okay, exiting...')
        return 
    
    new_fn = filename.resolve().with_name(filename.stem[:-4] + '_fixed_seg.npy')
    click.echo(f'{">" * 5} Saving fixed file to \t{str(new_fn)}')
    np.save(new_fn, file_data)
    click.echo('done.')
    click.echo('You will have to rename the `_fixed_seg.npy` to end in `_seg.npy` (remove `_fixed_seg.npy`)')


if __name__ == "__main__":
    main()

[mrariden]

Now the .color attribute is always saved as an int. All behavior is backwards compatible