How to use image_editor_output_format filter in WordPress

image_editor_output_format filter

Enables filtering the mime type used to save images. By default, the mapping array is empty, so the mime type matches the source image.

To use the image_editor_output_format filter, first, you have to register it using add_filter. You can write this code into the functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the below live example, we have defined a function weplugins_modify_image_editor_output_format_defaults which takes 3 parameters. We registered it using add_filter. The first parameter image_editor_output_format is the name of the hook, the second parameter weplugins_modify_image_editor_output_format_defaults is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times, and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook so you can use remove_filter to remove the image_editor_output_format filter.

Parameters

Below are the 3 parameters required to use this hook:

• $output_format : (string[]) An array of mime type mappings. Maps a source mime type to a new destination mime type. Default empty array.
• $filename : (string) Path to the image.
• $mime_type : (string) The source image mime type.

Live Examples

Example 1: Modifying Image Editor Output Format

Below is an example of how you can use this hook to modify the image editor output format.

    function weplugins_modify_image_editor_output_format_defaults($output_format, $filename, $mime_type) { 
        // Update the $output_format variable according to your website requirements and return this variable. 
        // You can modify the $output_format variable conditionally too if you want.
        return $output_format; 
    }
    // add the filter
    add_filter("image_editor_output_format", "weplugins_modify_image_editor_output_format_defaults", 10, 3);
    

Example 2: Removing a Hook Callback

To remove a hook callback, use the example below.

    remove_filter("image_editor_output_format", "weplugins_modify_image_editor_output_format_defaults", 10, 3);
    

Please make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Example 3: Conditional Mime Type Mapping

In this example, we conditionally change the mime type based on the file extension.

    function weplugins_conditional_mime_type_mapping($output_format, $filename, $mime_type) {
        $extension = pathinfo($filename, PATHINFO_EXTENSION);
        if ($extension == 'jpg') {
            $output_format['image/jpeg'] = 'image/webp';
        }
        return $output_format;
    }
    // add the filter
    add_filter("image_editor_output_format", "weplugins_conditional_mime_type_mapping", 10, 3);
    

Contact Us

If you’re having any trouble using this hook, please contact our WordPress Development Team and we’d be happy to assist you.