scale_up.py

import sys

if (len(sys.argv) != 3):
    print('Usage: '+sys.argv[0]+' geotiff_image.tif scale_factor')
    sys.exit()

filename = sys.argv[1]
scale_factor = int(sys.argv[2])

from osgeo import gdal

driver = gdal.GetDriverByName("GTiff")
def save(data, name):
    outData = driver.Create(name, data.shape[1], data.shape[0])
    outData.GetRasterBand(1).WriteArray(data)

import numpy as np
def scale_up(data):
    data = np.repeat(data, scale_factor, axis=0)
    data = np.repeat(data, scale_factor, axis=1)
    return data

data = gdal.Open(filename)
data = data.ReadAsArray()
data = scale_up(data)
save(data, 'out_x'+str(scale_factor)+'.tif')