Organising and display thousands of photos in media library

I had a very similar issue not so long ago, albeit, my scenario was allowing the user to select images by type of room, color, feature etc..

Using inspiration form this site: Inspiration and a combination of these two plugins, Custom Upload Dir, Media Tags it worked out quite well.

I dont think your going to be able to do what you want though without going through every image and tagging it in some form or other.

Again I had the same issue as developing a site AFTER uploading images. In the end I categorized all the images by type into folders on pc, then selected all images and whilst in windows,adding a tag to the copyright exif.. couldn’t workout how to get the keyword exif 🙂

Then using this piece of code, the copyright exif info got written to the meta tag (tag) on upload.

add_filter('wp_read_image_metadata', 'hk_filter_add_exif','',3);

//******************************************************************************************
// this hook function adds also the exif tag "copyright" in the database of each uploaded image
//******************************************************************************************
function hk_filter_add_exif($meta, $file, $sourceImageType)
{
    if ( is_callable('exif_read_data') &&
        in_array($sourceImageType, apply_filters('wp_read_image_metadata_types', array(IMAGETYPE_JPEG, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM)) ) )
    {

        $exif = @exif_read_data( $file );

        if (!empty($exif['Copyright']))      $meta['tags'] = $exif['Copyright'] ;

        return $meta;
    }
}

Could then use standard wordpress functions to get this tag info to use in the plugins.

This isnt an answer as such, but hopefully it may give you ideas.