{namespace v=FluidTYPO3\Vhs\ViewHelpers}
<div>
<v:condition.string.contains haystack="{data.flexform_item_link_href}" needle="http://">
    <f:then>
        <f:link.external uri="{data.flexform_item_link_href}" target="_blank">
            <img src="{f:cObject(typoscriptObjectPath: "lib.bannerImage", data: "{data.flexform_item_image}")}" alt="{data.flexform_item_image_title}" class="img-responsive" />
        </f:link.external>   
    </f:then>
    <f:else>
        <v:condition.string.contains haystack="{data.flexform_item_link_href}" needle="https://">
        <f:then>
            <f:link.external uri="{data.flexform_item_link_href}" target="_blank">
                <img src="{f:cObject(typoscriptObjectPath: "lib.bannerImage", data: "{data.flexform_item_image}")}" alt="{data.flexform_item_image_title}" class="img-responsive" />
            </f:link.external>
        </f:then>
        <f:else>
            <f:link.typolink parameter="{data.flexform_item_link_href}">
                <img src="{f:cObject(typoscriptObjectPath: "lib.bannerImage", data: "{data.flexform_item_image}")}" alt="{data.flexform_item_image_title}" class="img-responsive" />
            </f:link.typolink>
        </f:else>
        </v:condition.string.contains>
    </f:else>     
</v:condition.string.contains>
</div>