From c4fe04845df857c0450079aec42989024bba3316 Mon Sep 17 00:00:00 2001
From: Yogeshwaran <kyogeshwaran1504@gmail.com>
Date: Fri, 8 Aug 2025 14:09:08 +0530
Subject: [PATCH] Fix imshow to support array alpha values and add
 corresponding test

---
 lib/matplotlib/image.py                               | 11 +++++++++--
 .../tests/test_axes/test_imshow_alpha_array.py        | 11 +++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 lib/matplotlib/tests/test_axes/test_imshow_alpha_array.py

diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
index c1846f92608c..3894013ff665 100644
--- a/lib/matplotlib/image.py
+++ b/lib/matplotlib/image.py
@@ -903,6 +903,10 @@ def __init__(self, ax,
             **kwargs
         )
 
+        #support array value in imshow
+        if isinstance(self._alpha, np.ndarray):
+            self._set_alpha_for_array(self._alpha)
+
     def get_window_extent(self, renderer=None):
         x0, x1, y0, y1 = self._extent
         bbox = Bbox.from_extents([x0, y0, x1, y1])
@@ -1579,8 +1583,10 @@ def imsave(fname, arr, vmin=None, vmax=None, cmap=None, format=None,
 
     .. note::
 
-       If you want to save a single channel image as gray scale please use an
-       image I/O library (such as pillow, tifffile, or imageio) directly.
+   If *arr* is a single-channel (MxN) image and you want to save it as a grayscale image 
+   (instead of applying a colormap), consider using a dedicated image I/O library like 
+   Pillow, imageio, or tifffile. `imsave` will apply a colormap by default.
+
 
     Parameters
     ----------
@@ -1658,6 +1664,7 @@ def imsave(fname, arr, vmin=None, vmax=None, cmap=None, format=None,
         else:
             sm = mcolorizer.Colorizer(cmap=cmap)
             sm.set_clim(vmin, vmax)
+
             rgba = sm.to_rgba(arr, bytes=True)
         if pil_kwargs is None:
             pil_kwargs = {}
diff --git a/lib/matplotlib/tests/test_axes/test_imshow_alpha_array.py b/lib/matplotlib/tests/test_axes/test_imshow_alpha_array.py
new file mode 100644
index 000000000000..af2ce22f7ba2
--- /dev/null
+++ b/lib/matplotlib/tests/test_axes/test_imshow_alpha_array.py
@@ -0,0 +1,11 @@
+import matplotlib.pyplot as plt
+import numpy as np
+
+def test_imshow_alpha_array():
+    data = np.random.rand(10, 10)
+    alpha = np.linspace(0, 1, 100).reshape(10, 10)
+
+    fig, ax = plt.subplots()
+    im = ax.imshow(data, alpha=alpha)
+    plt.colorbar(im, ax=ax)
+    return fig