I am adding Gaussian Noise using the Keras GaussianNoise layer to my data to corrupt it to prevent overfitting. I have analysed my data and the mean of all values is 7624 and the standard deviation is 2591. I have attached a picture of the distribution too.

Approximately, which value should I choose as the standard deviation for my model. I am currently trying out a value of 500 because images generated by std of 1000 looked too noisy to me.