diff --git a/crop.jpg b/crop.jpg
deleted file mode 100644
index b239da7..0000000
Binary files a/crop.jpg and /dev/null differ
diff --git a/resize.py b/resize.py
index 0730a11..40b75bd 100755
--- a/resize.py
+++ b/resize.py
@@ -4,43 +4,51 @@ import os, sys
 from PIL import Image
 from PIL import ImageEnhance
 import argparse
+CROP_DEFAULT = 'default'
+CROP_WHITESPACE = 'whitespace'
 parser = argparse.ArgumentParser()
-parser.add_argument("--width", dest="width", type=int, required=True)
-parser.add_argument("--height", dest="height", type=int, required=True)
-parser.add_argument("--crop", action="store_true", required=False)
-parser.add_argument("--keep-aspect-ratio", dest="keep_aspect_ratio", action="store_true", required=False)
+parser.add_argument("--width", type=int)
+parser.add_argument("--height", type=int)
+parser.add_argument("--crop", choices=[CROP_WHITESPACE, CROP_DEFAULT])
+parser.add_argument("--enhance", action="store_true")
 parser.add_argument("source", type=str)
 parser.add_argument("destination", type=str)
 args = parser.parse_args()
 
-size = args.width, args.height
 infile = args.source
 outfile = args.destination
 try:
     im = Image.open(infile)
     im = im.convert()
-    if args.crop:
-        width_crop = im.size[0]
-        height_crop = int(im.size[0]/(args.width/args.height))
-        width_padding = 0
-        height_padding = int((im.size[1]-height_crop)/2)
-        if height_crop > im.size[1]:
-            width_crop = int(im.size[1]/(args.height/args.width))
-            height_crop = im.size[1]
-            width_padding = int((im.size[0]-width_crop)/2)
-            height_padding = 0
-        print((width_padding, height_padding, width_crop+width_padding, height_crop+height_padding))
-        im_crop = im.crop((width_padding, height_padding, width_crop+width_padding, height_crop+height_padding))
-        im_result = im_crop.resize(size, Image.ANTIALIAS)
-    else:
-        im.thumbnail(size, Image.ANTIALIAS)
-        if args.keep_aspect_ratio:
-            im_result = im
+    if args.width is not None or args.height is not None:
+        if args.width is None:
+            size = (int(im.size[0] * args.height / im.size[1]), args.height)
+        elif args.height is None:
+            size = (args.width, int(im.size[1] * args.width / im.size[0]))
         else:
-            im_result = Image.new('RGB', (args.width, args.height), (255, 255, 255))
-            im_result.paste(im, ((args.width - im.size[0]) / 2, (args.height - im.size[1]) / 2))
-    enhancer = ImageEnhance.Contrast(im_result)
-    im_result = enhancer.enhance(1.05)
-    im_result.save(outfile, "JPEG", quality=100)
+            size = (args.width, args.height)
+        if args.crop:
+            if args.crop == CROP_DEFAULT:
+                width_crop = im.size[0]
+                height_crop = int(im.size[0]/(size[0]/size[1]))
+                x = 0
+                y = int((im.size[1]-height_crop)/2)
+                if height_crop > im.size[1]:
+                    width_crop = int(im.size[1]/(size[1]/size[0]))
+                    height_crop = im.size[1]
+                    x = int((im.size[0]-width_crop)/2)
+                    y = 0
+                im = im.crop((x, y, width_crop+x, height_crop+y))
+            im.thumbnail(size, Image.ANTIALIAS)
+            if args.crop == CROP_WHITESPACE:
+                im_whitespace = Image.new('RGB', (size[0], size[1]), (255, 255, 255))
+                im_whitespace.paste(im, ((size[0] - im.size[0]) // 2, (size[1] - im.size[1]) // 2))
+                im = im_whitespace
+        else:
+            im.thumbnail(size, Image.ANTIALIAS)
+    if args.enhance:
+        enhancer = ImageEnhance.Contrast(im)
+        im = enhancer.enhance(1.05)
+    im.save(outfile, "JPEG", quality=100)
 except IOError:
     print("cannot create thumbnail for '%s'" % infile)
diff --git a/square.py b/square.py
deleted file mode 100755
index 9dec1f6..0000000
--- a/square.py
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/usr/bin/env python
-import argparse
-parser = argparse.ArgumentParser()
-parser.add_argument("square", type=int,
-                    help="display a square of a given number")
-parser.add_argument("-v", "--verbose", action="store_true",
-                    help="increase output verbosity")
-args = parser.parse_args()
-answer = args.square**2
-if args.verbose:
-    print("the square of {} equals {}".format(args.square, answer))
-else:
-    print(answer)
\ No newline at end of file
diff --git a/test_resize.sh b/test_resize.sh
new file mode 100755
index 0000000..70d98f9
--- /dev/null
+++ b/test_resize.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+./resize.py --width=100 origin.jpg resize_w100.jpg
+./resize.py --width=100 --crop default origin.jpg resize_w100_crop.jpg
+./resize.py --width=100 --crop whitespace origin.jpg resize_w100_crop_whitespace.jpg
+./resize.py --height=100 origin.jpg resize_h100.jpg
+./resize.py --height=100 --crop default origin.jpg resize_h100_crop.jpg
+./resize.py --height=100 --crop whitespace origin.jpg resize_h100_crop_whitespace.jpg
+./resize.py --width=100 --height=100 origin.jpg resize_w100_h100.jpg
+./resize.py --width=100 --height=100 --crop default origin.jpg resize_w100_h100_crop.jpg
+./resize.py --width=100 --height=100 --crop whitespace origin.jpg resize_w100_h100_crop_whitespace.jpg
+./resize.py --enhance origin.jpg enhance.jpg
\ No newline at end of file
diff --git a/thumbnail.jpg b/thumbnail.jpg
deleted file mode 100644
index 6ce539e..0000000
Binary files a/thumbnail.jpg and /dev/null differ