René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: alpha array-type not working with RGB image in imshow()","articleBody":"### Bug summary\n\nHi,\r\nWhereas `alpha = constant` works with RGB image, this is not the case when working with an `array-type` for alpha.\r\n(In my real case, I can only pass standard imshow parameters like `alpha `to the function of the library I use, and not a RGBA array).\r\nPatrick\n\n### Code for reproduction\n\n```python\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\nfrom skimage.color import gray2rgb\r\n\r\narr = np.random.random((10, 10))\r\narr_rgb = gray2rgb(arr)\r\n\r\nalpha = np.ones_like(arr)\r\nalpha[:5] = 0.2\r\n\r\nplt.figure()\r\nplt.tight_layout()\r\nplt.subplot(121)\r\nplt.title(\"Expected outcome\")\r\nplt.imshow(arr, alpha=alpha, cmap='gray')\r\nplt.subplot(122)\r\nplt.title(\"Actual outcome\")\r\nplt.imshow(arr_rgb, alpha=alpha)\r\nplt.show()\n```\n\n\n### Actual outcome\n\n![image](https://github.com/matplotlib/matplotlib/assets/16154687/89322c0b-4ccd-46e1-9f2a-50b5f3511dfa)\r\n\n\n### Expected outcome\n\n![image](https://github.com/matplotlib/matplotlib/assets/16154687/4d7fcedf-2c54-4f07-a35d-ad23afeb9df6)\r\n\n\n### Additional information\n\n_No response_\n\n### Operating system\n\nWindows\n\n### Matplotlib Version\n\n3.7.1\n\n### Matplotlib Backend\n\nTkAgg\n\n### Python version\n\nPython 3.10.11\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\npip","author":{"url":"https://github.com/patquem","@type":"Person","name":"patquem"},"datePublished":"2023-06-08T09:26:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":35},"url":"https://github.com/26092/matplotlib/issues/26092"}