resize multiple filetypes

[Guest]

Is there a possibility to resize multiple files of different formats at once, and resized files to be in the same format?
For example, several .jpg, .tiff and .gif files to be resized (batch convert) at 50% and resulting files to be in the source format (keeping originals intact)

As i can see, format must be given and the same.

Thank you.

[xnview]

Is there a possibility to resize multiple files of different formats at once, and resized files to be in the same format?
For example, several .jpg, .tiff and .gif files to be resized (batch convert) at 50% and resulting files to be in the source format (keeping originals intact)

As i can see, format must be given and the same.

Currently not possible, but i'll add it

[Guest]

Thank you.
Also consider adding it to nconvert if possible.