Yes,
@onebacklinkman is absolutely right images are just one factor that affects your page speed. Apart from images, there are several other factors that contribute to low page speed:
Server Performance
This is the direct cause when a user pings your website through their browser. If the hosting service you are using for your site is not working well for you it lowers down your page speed.
Also, the server location can be a cause for your low page speed. Farther the server from the server, longer the site will take to load.
Too Many Redirects
Redirects are inevitable but too many redirects can lower your page performance. Try eliminating those pages from your that are of no use or return error 404.
Too Many Plugins
Plugins help you extend the core features of the website design platform, but adding too many of them can bring a negative effect to your page speed. Remove the plugins that are not bringing any measurable benefit to your site.
Inefficient Codes
Speed also lowers when the search engine crawler has to render too many JavaScripts, page speed is compromised. Try minifying your CSS and HTML files and also, avoid using too many JavaScripts.
Thank You !!