<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def resize_compute_width_height(fullfile,_megapixels):
 """Given image file and desired megapixels, computes the new width and height"""


    img = Image.open(fullfile)
    width,height=img.size

    current_megapixels=width*height/(2.0**20)
    scale=sqrt(_megapixels/float(current_megapixels))

    logger.debug('A resize scale would be %f'%(scale))
    # Can't make bigger, return original
    if scale>= 1.0:
        logger.warning('Image is %0.1f MP, trying to scale to %0.1f MP - just using original!',
                current_megapixels,_megapixels);
        return width,height

    new_width=int(width*scale)
    new_height=int(height*scale)

    return new_width,new_height