I have a theme where when the user edits images, I want the changes to apply to "all sizes except for thumbnails".
She remembers to check this box most of the time, but not always, and it is very aesthetically unappealing on one page when she doesn't. Also; it's kind of a pain for here to have to check the box every time.
I found in
/wp-admin/includes/image-edit.php where the default is set -> happens on line 133 with:
<input type="radio" name="imgedit-target-<?php echo $post_id; ?>" value="all" checked="checked" /> <?php _e('All image sizes'); ?></label>
But I'm kind of new to WP, and I don't really know what to do with this knowlege. It's easy enough to implement in the front or the backend; I just haven't figured out when, where, or how.