Improve your site's SEO with the best solution for completely Search Engine Optimizing images and dynamically fixing HTML validation errors.
Select default settings for image link when you upload or insert images. Select default image link to None, Attachment Page, Media File or Custom URL.
Automatically Link images to none in selecting and uploading images in WordPress
The plugin automatically adds “ALT tags” to all images on your site, that do not have a manually set ALT tags, using a smart scan for the best SEO
Magic SEO Image For NextGen helps you improve SEO of your images by easing bulk images ALT changing for NextGen gallery
THIS PLUGIN IS AN OLD UNSUPPORTED VERSION, FOR NEW VERSION SEE SEO Image Tags (https://wordpress.org/plugins/seo-image-alt-tags/)