Please find below a way that works on all browsers. Basically I put the input on top the image. I make it huge using font-size so the user is always clicking the upload button.
.myFile {_x000D_
position: relative;_x000D_
overflow: hidden;_x000D_
float: left;_x000D_
clear: left;_x000D_
}_x000D_
.myFile input[type="file"] {_x000D_
display: block;_x000D_
position: absolute;_x000D_
top: 0;_x000D_
right: 0;_x000D_
opacity: 0;_x000D_
font-size: 100px;_x000D_
filter: alpha(opacity=0);_x000D_
cursor: pointer;_x000D_
}
_x000D_
<label class="myFile">_x000D_
<img src="http://wscont1.apps.microsoft.com/winstore/1x/c37a9d99-6698-4339-acf3-c01daa75fb65/Icon.13385.png" alt="" />_x000D_
<input type="file" />_x000D_
</label>
_x000D_