from the looks of this code it appears you are doing data-binding. you can transform data before it is presented in the view
http://docs.appcelerator.com/titanium/latest/#!/guide/Alloy_Data_Binding
<TableView id="brandsList" dataCollection="brands" dataTransform="transformFunction">
<TableViewRow brandID="{brand_id}">
<View class="vgroup">
<ImageView height="45" width="80" id="image" image="{image}" />
<Label id="name" text="{name}" />
</View>
</TableViewRow>
</TableView>
then in the code
function transformFunction(model) {
// Need to convert the model to a JSON object
var transform = model.toJSON();
transform.image = /* do someting to image url string */;
return transform;
}