Fix y/x being the wrong way around

Author: halcy

blurhash/__init__.py

@@ -1,4 +1,7 @@
 from .blurhash import blurhash_encode as encode
 from .blurhash import blurhash_decode as decode
+from .blurhash import blurhash_components as components
+from .blurhash import srgb_to_linear as srgb_to_linear
+from .blurhash import linear_to_srgb as linear_to_srgb
 
-__all__ = ['encode', 'decode']
+__all__ = ['encode', 'decode', 'components', 'srgb_to_linear', 'linear_to_srgb']

blurhash/blurhash.py

@@ -60,6 +60,20 @@ def linear_to_srgb(value):
         return int(value * 12.92 * 255 + 0.5)
     return int((1.055 * math.pow(value, 1 / 2.4) - 0.055) * 255 + 0.5)
 
+def blurhash_components(blurhash):
+    """
+    Decodes and returns the number of x and y components in the given blurhash.
+    """
+    if len(blurhash) < 6:
+        raise ValueError("BlurHash must be at least 6 characters long.")
+    
+    # Decode metadata
+    size_info = base83_decode(blurhash[0])
+    size_y = int(size_info / 9) + 1
+    size_x = (size_info % 9) + 1
+    
+    return size_x, size_y
+
 def blurhash_decode(blurhash, width, height, punch = 1.0, linear = False):
     """
     Decodes the given blurhash to an image of the specified size.
@@ -80,8 +94,8 @@ def blurhash_decode(blurhash, width, height, punch = 1.0, linear = False):
 
     # Decode metadata
     size_info = base83_decode(blurhash[0])
-    size_x = int(size_info / 9) + 1
-    size_y = (size_info % 9) + 1
+    size_y = int(size_info / 9) + 1
+    size_x = (size_info % 9) + 1
 
     quant_max_value = base83_decode(blurhash[1])
     real_max_value = (float(quant_max_value + 1) / 166.0) * punch

tests/test_blurhash.py

@@ -18,6 +18,25 @@ def test_decode():
     reference_image = np.load(os.path.join(base_path, "blurhash_out.npy"))
     assert np.sum(np.abs(image - reference_image)) < 1.0
 
+def test_asymmetric():
+    image = PIL.Image.open(os.path.join(base_path, "cool_cat.jpg"))
+    blur_hash = blurhash.encode(np.array(image.convert("RGB")), components_x = 2, components_y = 8)
+    assert blur_hash == "%BMOZfK1BBNG2skqs9n4?HvgJ.Nav}J-$%sm"
+    
+    decoded_image = blurhash.decode(blur_hash, 32, 32)
+    assert np.sum(np.var(decoded_image, axis = 0)) > np.sum(np.var(decoded_image, axis = 1))
+
+    blur_hash = blurhash.encode(np.array(image.convert("RGB")), components_x = 8, components_y = 2)
+    decoded_image = blurhash.decode(blur_hash, 32, 32)
+    assert np.sum(np.var(decoded_image, axis = 0)) < np.sum(np.var(decoded_image, axis = 1))
+
+def test_components():
+    image = PIL.Image.open(os.path.join(base_path, "cool_cat.jpg"))
+    blur_hash = blurhash.encode(np.array(image.convert("RGB")), components_x = 8, components_y = 3)
+    size_x, size_y = blurhash.components(blur_hash)
+    assert size_x == 8
+    assert size_y == 3
+
 def test_linear_dc_only():
     image = PIL.Image.open(os.path.join(base_path, "cool_cat.jpg"))
     linearish_image = np.array(image.convert("RGB")) / 255.0