Image size affecting ranking

Probably a noob question, but I read on moz that images above 1024 x 768 affect SEO negatively. Say I had an image thats like 2000 x 1000 one a portfolio page. Would that image affect the home page ranking?

The images probably don't affect anything, except for image search parameters(where searchers can filter and sort by size) but page load times do matter, so if your 2mp image is taking a year to load that's certainly gonna have an impact.

This high quality Images just makes your website slow just that's the problem!

Yep image size just affect page load...
To improve load time when you are saving pictures use "progressive" save method...

Like others have said the large images makes your pages load slow which does affect your bounce rate and in return
can mess with your rankings

When it comes to choosing images for a website both image size and quality are important.

The point is that lower quality images decrease site load time, but detract from the visual effect required. High quality images look great, but cause pages to load slowly, which is bad from an SEO prospective.

For large images, it is best to place a small thumbnail image next to the description, and then link it to a high quality Image. Also, if you are offering very large images, you might want to put them on a separate website page so that only users who are really interested can see the images full-size view.