diff --git a/binary_image_palette.py b/binary_image_palette.py
deleted file mode 100644
index bc967e7..0000000
--- a/binary_image_palette.py
+++ /dev/null
@@ -1,78 +0,0 @@
-import struct
-import sys
-
-from PIL import Image
-
-def round_up_palette_size(palette_size):
-    assert palette_size != 0, (name, palette_size)
-    if palette_size <= 4:
-        return 4
-    elif palette_size <= 16:
-        return 16
-    elif palette_size <= 256:
-        return 256
-    else:
-        assert False, palette_size
-
-def pixels_per_byte(palette_size):
-    if palette_size == 4:
-        return 4
-    elif palette_size == 16:
-        return 2
-    elif palette_size == 256:
-        return 1
-    else:
-        assert False, palette_size
-
-def pack_one_byte(pixels, index, colors, palette_size):
-    color_count = len(colors)
-    num = pixels_per_byte(palette_size)
-    shift = 8 // num
-    byte = 0
-    i = 0
-    while num > 0:
-        px, alpha = pixels[index]
-        if alpha == 0 and color_count < palette_size:
-            px = color_count
-        assert px < palette_size
-        byte |= px << (shift * i)
-        index += 1
-        i += 1
-        num -= 1
-    return [byte], index
-
-def pack_one_texel(pixels, index, colors, palette_size):
-    px, alpha = pixels[index]
-    return
-
-def pack_pixels(pixels, width, height, colors, palette_size):
-    index = 0
-    with open(sys.argv[2], 'wb') as f:
-        while index < (width * height):
-            byte_list, index = pack_texel(pixels, index, colors, palette_size)
-            f.write(bytes(byte))
-
-def pack_palette(colors, palette_size):
-    with open(sys.argv[2], 'wb') as f:
-        for color in colors:
-            out = argb1555(255, *color)
-            f.write(struct.pack('<H', out))
-        if len(colors) < palette_size:
-            # transparent color
-            print('pack transparency at ix', len(colors))
-            out = argb1555(0, 0, 0, 0)
-            f.write(struct.pack('<H', out))
-
-with Image.open(sys.argv[1]) as im:
-    assert im.mode == "P"
-    width, height = im.size
-    colors = list(im.palette.colors)
-    pixels = list(im.convert("PA").getdata())
-
-palette_size = round_up_palette_size(len(colors))
-if sys.argv[2].endswith('.data'):
-    pack_pixels(pixels, width, height, len(colors), palette_size)
-elif sys.argv[2].endswith('.pal'):
-    pack_palette(colors, palette_size)
-else:
-    assert False, sys.argv[2]
diff --git a/color_convert.py b/color_convert.py
new file mode 100644
index 0000000..13924da
--- /dev/null
+++ b/color_convert.py
@@ -0,0 +1,92 @@
+import struct
+import sys
+
+from PIL import Image
+
+class color_format:
+    def gbgr1555(r, g, b, a): # nintendo ds
+        r5 = (r >> 3) & 31
+        g6 = (g >> 3) & 31
+        g6_l = (g >> 2) & 1
+        b5 = (b >> 3) & 31
+        return (g6_l << 15) | (b5 << 10) | (g6 << 5) | (r5 << 0)
+
+    def argb4444(r, g, b, a):
+        a4 = (a >> 4) & 15
+        r4 = (r >> 4) & 15
+        g4 = (g >> 4) & 15
+        b4 = (b >> 4) & 15
+        return (a4 << 12) | (r4 << 8) | (g4 << 4) | (b4 << 0)
+
+    def argb1555(r, g, b, a):
+        a1 = (a >> 7) & 1
+        r5 = (r >> 3) & 31
+        g5 = (g >> 3) & 31
+        b5 = (b >> 3) & 31
+        return (a1 << 15) | (r5 << 10) | (g5 << 5) | (b5 << 0)
+
+    def rgb565(r, g, b, a):
+        r5 = (r >> 3) & 31
+        g6 = (g >> 2) & 63
+        b5 = (b >> 3) & 31
+        return (r5 << 11) | (g5 << 5) | (b5 << 0)
+
+    def from_string(s):
+        return dict([
+            ("gbgr1555", color_format.gbgr1555),
+            ("argb4444", color_format.argb4444),
+            ("argb1555", color_format.argb1555),
+            ("rgb565", color_format.rgb565),
+        ])[s]
+
+in_file = sys.argv[1]
+format = sys.argv[2]
+out_file = sys.argv[3]
+
+palette = None
+
+with Image.open(in_file) as im:
+    width, height = im.size
+    if not im.palette:
+        pixels = list(im.convert("RGBA").getdata())
+    else:
+        pixels = list(im.convert("P").getdata())
+        palette = list(im.palette.colors)
+
+has_alpha = False
+convert = color_format.from_string(format)
+
+def convert_colors(f, colors):
+    for color in colors:
+        value = convert(*color)
+        f.write(struct.pack("<H", value))
+
+if palette is None:
+    with open(out_file, 'wb') as f:
+        convert_colors(f, pixels)
+else:
+    with open(out_file, 'wb') as f:
+        if len(palette) <= 4:
+            for i in range(len(pixels) // 4):
+                a = pixels[i * 4 + 0]
+                b = pixels[i * 4 + 1]
+                c = pixels[i * 4 + 2]
+                d = pixels[i * 4 + 3]
+                assert a <= 3 and b <= 3 and c <= 3 and d <= 3, (a, b, c, d)
+                pixel = (d << 6) | (c << 4) | (b << 2) | (a << 0)
+                f.write(struct.pack("<B", pixel))
+        elif len(palette) <= 16:
+            for i in range(len(pixels) // 2):
+                a = pixels[i * 2 + 0]
+                b = pixels[i * 2 + 1]
+                assert a <= 15 and b <= 15, (a, b)
+                pixel = (b << 4) | (a << 0)
+                f.write(struct.pack("<B", pixel))
+        elif len(palette) <= 256:
+            for pixel in pixels:
+                assert pixel <= 255
+                f.write(struct.pack("<B", pixel))
+        else:
+            assert False, len(palette)
+    with open(out_file + '.pal', 'wb') as f:
+        convert_colors(f, [(*c, 255) for c in palette])