Isolating a particular area from a raster

[AlexanderThompson]

I am new to GIS so apologies if I am not using all the right terminology here. There is something I could really use some help with. I have a single-band image as a raster layer and I am looking for a way to analyze only part of that image rather than the whole thing. I will be looking at the StDev of band 1 in that portion of the image. Is there a way that I could outline a custom area, similar to how you draw an area with measuring tool, to cut out part of the image and make it into its own raster layer? Thank you in advance.

Edit: I want to add that I have found the raster clip tool, however this only does a rectangle and I need a complex shape. Also, when I try to use it the clipped part of it becomes altered and looks different.

[JayantaPoddar]

If you have the shape in the form of a polygon feature layer, you could use Clip Raster (Data Management).

Output Extent: Feature Layer

Check "Use Input Features for Clipping Geometry"

[DanPatterson · Accepted solution]

extract by mask

you can draw a polygon or select a pre-drawn featureclass