I want to ask that,
If I change the images on my homepage very often, will Google like it as they like content update(text)?

Will I rank better than a competitor site that never changes its images?
Thank in advance for your positive help.

Yes, Google will like it but don't forget to add the ALT attribute with some unique description.

Hi.
Definitely you will rank better. But add some description in an image. Image must be relevant to your site.

HI
use ALT tag if you using images, and use images which are relevant to the content.

Good things here I found thanks for sharing.

Yes, definitely Google will consider this update as a part of content optimization but most important is image should be enclosed with the important image attribute 'ALT'. This is the only way through with Google can read the image.