'**SUMMARY**
Resize every image in the set to a standard size.
**PARAMETERS**
* *width* - the width that we want for every image in the set.
* *height* - the height that we want for every image in the set.
**RETURNS**
A new image set where every image in the set is scaled to the desired size.
**EXAMPLE**
>>>> iset = ImageSet("./b/")
>>>> thumbnails = iset.standardize(64,64)
>>>> for t in thumbnails:
>>>>   t.show()'

def standardize(self, width, height):

    retVal = ImageSet()
    for i in self:
        retVal.append(i.resize(width, height))
    return retVal
