WordPress at a glance
filter is not described

wp_image_editor_before_change filter-hook . WP 3.5.0

Filters the WP_Image_Editor instance before applying changes to the image.

Usage

add_filter( 'wp_image_editor_before_change', 'filter_function_name_7265', 10, 2 );
function filter_function_name_7265( $image, $changes ){
	// filter...

	return $image;
}
$image(WP_Image_Editor)
WP_Image_Editor instance.
$changes(array)
Array of change operations.

Where the hook is called

image_edit_apply_changes()
wp_image_editor_before_change
wp-admin/includes/image-edit.php 553
$image = apply_filters( 'wp_image_editor_before_change', $image, $changes );

Where the hook is used (in WP core)

Does not used.