The 'ngStyle' directive allows you to set CSS style on an HTML element conditionally.
Much like how we could use style attribute on HTML element in non-AngularJS projects, we can use ng-style in angularjs do apply styles based on some boolean condition.
<ANY ng-style="expression"></ANY >
<ANY class="ng-style: expression;"> ... </ANY>
Below example changes the opacity of the image based on the "status" parameter.
<img class="img-responsive" ng-src="{{imagesrc}}"
ng-style="{'opacity' : (status == 2) ? 1 : 0.5}">