- Firstly optimization images for search-engines like Google is like optimizing images for blind people signifying that Google is incapable of crawling images while going through the content of the website. Find-ability of website does not depend upon the searches or the traffic driven towards it but it is directly proportional to content of the website.
If you want that your image should be successfully crawled by Google you need to take care of these issues and help Google to indexing your image:
Google can crawl both the HTML page the image is embedded in, and the image itself.
The image should be in Google supported formats: BMP, GIF, JPEG, PNG, WebP or SVG.
While applying images to your website like you said MIME type images, you must have used/download after the URL of the image due to which your image get downloaded and are not directly visible on the page so you need to remove “/download” from end of URL’s and instead use the following tags which will enable the picture to directly get visible on page.
image/gif: GIF image; Defined in RFC 2045 and RFC 2046
image/jpeg: JPEG JFIF image; Defined in RFC 2045 and RFC 2046
image/pjpeg: JPEG JFIF image; Associated with Internet Explorer; Listed in ms775147(v=vs.85) – Progressive JPEG, initiated before global browser support for progressive JPEGs (Microsoft and Firefox).
image/png: Portable Network Graphics; Registered, Defined in RFC 2083
image/svg+xml: SVG vector image; Defined in SVG Tiny 1.2 Specification Appendix M
image/vnd.djvu: DjVu image and multipage document format.
image/example: example in documentation, Defined in RFC 4735
Lastly up with the Effect of MIME type image on SEO of website, here I can say that by using Alt Tags you directly drive 50% of traffic towards the site if you use the indexing formats mentioned by Google due to which your image gets indexed by it. Getting to the core part yes, it does effects as it enhances the view of your site and if you use influential images people may get their answers by just looking at images.