autoScaleImageCLim(hImage) automatically updates the specified image's axis CLim property to the 10th & 90th percentiles of CData values for the displayed portion of the image. This CLim is automatically updated whenever the image is updated, zoomed, panned or modified in any way.

autoScaleImageCLim(hImage, threshold) recalculates CLim based on a user-specified threshold (default: 10). For example, if threshold=5, then the 5% and 95% CData values are used for CLim. This threshold can be specified as either a number in the range [1-49] (indicating full percentage), or as a corresponding numeric fraction in the range [0-0.49].

Inputs:
hImage - handle to a Matlab image object (optional; default=current image)
threshold - threshold for setting CLim (optional; default=10)

Examples:
autoScaleImageCLim() % auto-scale the current axes' image
autoScaleImageCLim(hImage,5) % auto-scale image using 5%-95% CData limits
autoScaleImageCLim(hImage,.07) % auto-scale image using 7%-93% CData limits

Warning:
This code relies on undocumented and unsupported Matlab functionality.
It works on Matlab R2014b or newer, but use at your own risk!

Technical explanation:
A technical explanation of the code in this utility can be found on http://undocumentedmatlab.com/blog/auto-scale-image-colors