How to Change Specific Position's Color with matplotlib.pyplot.imshow

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Changing Colors in a Numpy Array with Matplotlib

The Problem

You're working with a numpy array that represents an image, and you want to change the color of specific pixels at defined positions. For instance, you might have an array representing a grayscale image and you’d like to highlight certain points (like features or data anomalies) with different colors.

Here's the scenario you have:

You have a numpy array that defines the image.

You also have a list of positions (coordinates) that indicate which pixels you want to change.

Example of the Current Setup

For demonstration, let's assume you have an initial image represented as follows:

[[See Video to Reveal this Text or Code Snippet]]

You might have specific positions in a list like this:

[[See Video to Reveal this Text or Code Snippet]]

The Solution

To modify the pixel color at the specified positions in the array, you'll need to access and change the pixel values of your numpy array directly. Here’s a simple approach to do that.

Step-by-Step Guide

Import Required Libraries:
Ensure you have both numpy and matplotlib libraries imported.

Define Your Image:
Create your numpy array (the image).

Set New Pixel Values:
Iterate over the list of positions and update the pixel values based on the desired colors.

Sample Code

Here’s how you might implement this:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code:

We then create a list of positions (pos) where we want to change the colors along with their corresponding values in another list (values_to_set).

Conclusion

Now you can apply this technique in your projects to emphasize important features in your image data. Happy coding!