How to (ab)use image effects to serve API generated images? I made code to add a custom effect using hook_image_effect_info() that does not alter the image for real. I'd like to serve an image from my own API instead, that has calls like myapi.com/img2123?w=25&amp;h=88&amp;watermark=true. I don't think that the code for a placeholder effect is relevant is it?

I'd like to use this because that way if I add an Image field to a content type I can choose a banner for example on every 'Article' content type.also I need to pass the parameter returned by the dimensions callback (set in the form callback of hook_image_effect_info()) to the GET request as an URL parameter.

I was thinking: could I use some node altering hook to change the uri that is parsed somewhere else in the program?

If you need some additional info, just ask. Thanks in advance.
If you are getting the image from another server/site you don't need an image field. If the link isn't going to change, you can store it in a text field and build a link like this

your_module_node_view($node, $view_mode, $langcode) {
    $url = $node-&gt;field_cool_image[LANGUAGE_NONE][0]['value'];
    //redefine field_cool_image to display your image
    $node['content']['field_cool_image'][0] = array(
        '#markup' = '&lt;img src="' . $url . '" alt="my cool image" /&gt;'
    );

}


otherwise build the link when the node view is built.

your_module_node_view($node, $view_mode, $langcode){
    //whatever method you use to build a url
    $url = my_build_url($node);
    $node-&gt;['content']['my_cool_img'][0] = array(
        '#markup' = '&lt;img src="' . $url . '" alt="my cool image" /&gt;'
    );
}