@gianny,

where do you need to filter the images in the front end or back end. we’ll see if we can create a simple filter.

Add this code to a theme of module make sure that use a unique name for the function “MY_THEME_filter_image_by_image_meta”

function MY_THEME_filter_image_by_image_meta( ){
global $ImStore;
if( empty( $ImStore->attachments ) || ! is_array( $ImStore->attachments  ) )
return false;
foreach( $ImStore->attachments as $key => $attachment ){
if( empty( $attachment->meta['image_meta']['credit'] ) 
|| $attachment->meta['image_meta']['credit'] !== 000 )
unset(  $ImStore->attachments[$key] );
}
} 
add_filter( 'ims_before_galleries', 'MY_THEME_filter_image_by_image_meta' );