How to Set Button image in XML Correctly - XML in SharePoint

Hello All,

Why Cannot I see the image in the Ribbon Button image?

I have written XML code for creating a ribbon button in SharePoint 2010

Button and function is executing fine but the image which I mapped is
 
not displaying properly, either it is blank button image or X mark. But I checked the

button properties in the output site and its property detail showing, it is attached

Image Size I Set in MS-paint it is as 32x32 px

Anything Wrong with this code???????? Or  Something Else??????

Image32by32="/_layouts/images/ribboniconTP.png"/>

Code Snippet : Elements.xml
   ------------------------------

Button Id="Contoso.Ribbon.CustomAction.Button"
								Alt="Custom Action"
								Sequence="30"
								Command="Contoso.Ribbon.DemoCommand"
								LabelText="App Button"
								TemplateAlias="o1"
               Image32by32="/_layouts/images/ribboniconTP.png"/>

Image:

------------