Fix XYB conversion

coloraide/__meta__.py

@@ -193,5 +193,5 @@ def parse_version(ver: str) -> Version:
     return Version(major, minor, micro, release, pre, post, dev)
 
 
-__version_info__ = Version(4, 4, 0, "final")
+__version_info__ = Version(4, 4, 1, "final")
 __version__ = __version_info__._get_canonical()

coloraide/spaces/xyb.py

@@ -25,35 +25,36 @@
     [-3.6588512867136815, 2.712923045936092, 1.945928240777589]
 ]
 
-# https://twitter.com/jonsneyers/status/1605321352143331328
-# @jonsneyers Feb 22
-# Yes, the default is to just subtract Y from B. In general there are locally
-# signaled float multipliers to subtract some multiple of Y from X and some
-# other multiple from B. But this is the baseline, making X=B=0 grayscale.
-# ----
-# We adjust the matrix to subtract Y from B match this statement.
 XYB_LMS_TO_XYB = [
     [0.5, -0.5, 0.0],
     [0.5, 0.5, 0.0],
-    [0.0, -1.0, 1.0],
+    [0.0, 0.0, 1.0]
 ]
 
 XYB_TO_XYB_LMS = [
     [1.0, 1.0, 0.0],
     [-1.0, 1.0, 0.0],
-    [-1.0, 1.0, 1.0]
+    [0.0, 0.0, 1.0]
 ]
 
 
 def rgb_to_xyb(rgb: Vector) -> Vector:
     """Linear sRGB to XYB."""
 
-    return alg.matmul_x3(
+    xyb = alg.matmul_x3(
         XYB_LMS_TO_XYB,
         [alg.nth_root(c + BIAS, 3) - BIAS_CBRT for c in alg.matmul_x3(LRGB_TO_LMS, rgb, dims=alg.D2_D1)],
         dims=alg.D2_D1
     )
 
+    # https://twitter.com/jonsneyers/status/1605321352143331328
+    # @jonsneyers Feb 22
+    # Yes, the default is to just subtract Y from B. In general there are locally
+    # signaled float multipliers to subtract some multiple of Y from X and some
+    # other multiple from B. But this is the baseline, making X=B=0 grayscale.
+    xyb[2] -= xyb[1]
+    return xyb
+
 
 def xyb_to_rgb(xyb: Vector) -> Vector:
     """XYB to linear sRGB."""
@@ -62,6 +63,7 @@ def xyb_to_rgb(xyb: Vector) -> Vector:
     if not any(xyb):
         return [0.0] * 3
 
+    xyb[2] += xyb[1]
     return alg.matmul_x3(
         LMS_TO_LRGB,
         [(c + BIAS_CBRT) ** 3 - BIAS for c in alg.matmul_x3(XYB_TO_XYB_LMS, xyb, dims=alg.D2_D1)],

docs/src/markdown/about/changelog.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 4.4.1
+
+-   **FIX**: Fix XYB transform.
+
 ## 4.4
 
 -   **NEW**: Add support for the CAM02 color model and add the CAM02 JMh, CAM02 UCS, CAM02 SCD, and CAM02 LCD color

docs/src/markdown/demos/3d_models.html

@@ -919,7 +919,7 @@ <h1>ColorAide Color Space Models</h1>
 let colorSpaces = null
 let colorGamuts = null
 let lastModel = null
-let package = 'coloraide-4.4-py3-none-any.whl'
+let package = 'coloraide-4.4.1-py3-none-any.whl'
 const defaultSpace = 'lab'
 const defaultGamut = 'srgb'
 const exceptions = new Set(['hwb', 'ryb', 'ryb-biased'])

docs/src/markdown/demos/colorpicker.html

@@ -421,7 +421,7 @@ <h1>ColorAide Color Picker</h1>
     let pyodide = null
     let webspace = ''
     let initial = 'oklab(0.69 0.13 -0.1 / 0.85)'
-    let package = 'coloraide-4.4-py3-none-any.whl'
+    let package = 'coloraide-4.4.1-py3-none-any.whl'
 
     const base = `${window.location.origin}/${window.location.pathname.split('/')[1]}/playground/`
     package = base + package

docs/src/mkdocs.yml

@@ -319,7 +319,7 @@ extra_css:
 extra_javascript:
   - https://cdn.jsdelivr.net/npm/ace-builds@1.39.0/src-min-noconflict/ace.js
   - https://cdn.jsdelivr.net/npm/mermaid@11.5.0/dist/mermaid.min.js
-  - playground-config-362fea92.js
+  - playground-config-d112cc38.js
   - https://cdn.jsdelivr.net/pyodide/v0.27.3/full/pyodide.js
   - assets/coloraide-extras/extra-notebook.js
 

docs/theme/playground-config-362fea92.js → docs/theme/playground-config-d112cc38.js

@@ -1,5 +1,5 @@
 var colorNotebook = {
-    "playgroundWheels": ['micropip', 'pygments-2.19.1-py3-none-any.whl', 'coloraide-4.4-py3-none-any.whl'],
-    "notebookWheels": ['pyyaml', 'Markdown-3.7-py3-none-any.whl', 'pymdown_extensions-10.14.3-py3-none-any.whl', 'micropip', 'pygments-2.19.1-py3-none-any.whl', 'coloraide-4.4-py3-none-any.whl'],
+    "playgroundWheels": ['micropip', 'pygments-2.19.1-py3-none-any.whl', 'coloraide-4.4.1-py3-none-any.whl'],
+    "notebookWheels": ['pyyaml', 'Markdown-3.7-py3-none-any.whl', 'pymdown_extensions-10.14.3-py3-none-any.whl', 'micropip', 'pygments-2.19.1-py3-none-any.whl', 'coloraide-4.4.1-py3-none-any.whl'],
     "defaultPlayground": "import coloraide\ncoloraide.__version__\nColor('red')"
 }

mkdocs.yml

@@ -319,7 +319,7 @@ extra_css:
 extra_javascript:
   - https://cdn.jsdelivr.net/npm/ace-builds@1.39.0/src-min-noconflict/ace.js
   - https://cdn.jsdelivr.net/npm/mermaid@11.5.0/dist/mermaid.min.js
-  - playground-config-362fea92.js
+  - playground-config-d112cc38.js
   - https://cdn.jsdelivr.net/pyodide/v0.27.3/full/pyodide.js
   - assets/coloraide-extras/extra-notebook-CuRWK8GL.js
 

tests/test_xyb.py

@@ -9,13 +9,13 @@ class TestXYB(util.ColorAssertsPyTest):
     """Test XYB."""
 
     COLORS = [
-        ('red', 'color(--xyb 0.0281 0.48819 0.01157)'),
-        ('orange', 'color(--xyb 0.01132 0.64596 -0.10359)'),
+        ('red', 'color(--xyb 0.0281 0.48819 -0.01653)'),
+        ('orange', 'color(--xyb 0.01132 0.64596 -0.1149)'),
         ('yellow', 'color(--xyb 0 0.81867 -0.20719)'),
-        ('green', 'color(--xyb -0.0091 0.36999 -0.17163)'),
+        ('green', 'color(--xyb -0.0091 0.36999 -0.16253)'),
         ('blue', 'color(--xyb 0 0.27813 0.38801)'),
-        ('indigo', 'color(--xyb 0.00704 0.18547 0.18989)'),
-        ('violet', 'color(--xyb 0.01268 0.60656 0.15033)'),
+        ('indigo', 'color(--xyb 0.00704 0.18547 0.18285)'),
+        ('violet', 'color(--xyb 0.01268 0.60656 0.13766)'),
         ('white', 'color(--xyb 0 0.84531 0)'),
         ('gray', 'color(--xyb 0 0.44741 0)'),
         ('black', 'color(--xyb 0 0 0)'),