title: insert image in a 'background-image' from a pipe
body: <p>I have the following code in my html document:</p>
  
  <pre><code>&lt;div *ngFor="let search of this.mySearches; let i = index" class="col-sm-6 col-xs-12"&gt;
                    &lt;div class="box"&gt;
                      &lt;div class="image img-search-rounded"&gt;
                        &lt;img [src]="search.postPath | imagenpost: search.generic_category: search.postImg[0]" alt="image" title="image" id="img-rounded" class="img-responsive img-rounded"&gt;
                      &lt;/div&gt;
                      &lt;div class="pull-left"&gt;
                        &lt;h4&gt;{{search.generic_category}}&lt;i class="la la-angle-double-right"&gt;&lt;/i&gt;{{search.generic_type}}&lt;/h4&gt;
                        &lt;p&gt;&lt;i class="la la-map-marker"&gt;&lt;/i&gt;{{search.generic_city}}&lt;/p&gt;
                        &lt;p&gt;&lt;i class="la la-clock-o"&gt;&lt;/i&gt; {{search.date | date:'medium'}}&lt;/p&gt;
                        &lt;p&gt;&lt;i class="la la-circle"&gt;&lt;/i&gt; Get email notifications&lt;/p&gt;
                      &lt;/div&gt;
                      &lt;div class="pull-right"&gt;
                        &lt;button type="button" [routerLink]="search.url"&gt;View&lt;/button&gt;
                        &lt;button type="button" (click)="removeMySearch(search._id)"&gt;Delete&lt;/button&gt;
                      &lt;/div&gt;
                    &lt;/div&gt;
                  &lt;/div&gt;
  </code></pre>
  
  <p>but I get this and not the image:</p>
  
  <p><a href="https://i.stack.imgur.com/I8eUR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I8eUR.png" alt="error image"></a></p>
  
  <p>How could I render the image?</p>