Please share useful tips or technique for image optimizations.

Tip for Image optimization

(1) Image Size
(2) Image Color Resolution
(3) Image Name
(4) Image Alt Tag

Images are a core element of your websites, and attractive images play a crucial role for user attention. But many sites fail to optimize their images. Not only can image optimization increase load times, but it can also improve search engine visibility.

More information read our blog https://risingworldtechnologies.wordpress.com/2015/04/01/top-10-helpful-techniques-for-image-optimization-to-get-search-ranking/

You need to use alt image tags with specific keyword for that image only, this will help you to gain serch engine ranking at Google..

Following are the four most needed and must notable things in image optimization process such as:
1. Alt text
2. File size
3. File Name
4. Captions
These are the fourmost must needed notable things in image optimization

the most important things are alt/title but dont forget the image file name.

Most important is File name
Before put Online you should change your image name as your targeted keyword and do some submission on High PR site like imgur
That's what i used to do. Thanks

Yes If we optimize the images, images do rank in Search engine.

While uploading images, make sure to give proper image name. Since Search engine can't understand or read images, we need to add ALT Tag, which is HTML syntax to let the Search Engine knows about images.

Compress the image.. Use alt tags and use your focus keyword..

you just need to do, resize if the image size is larger than required. Consider always Image Size, alt tag of the image.
Update ALT Tags for all of the images with a specific keyword you are using. It will help you to get good search ranking position on the Search Engine Results Pages (SERP).

Some common tips to optimize images:

  1. Choose the right file format
  2. Reduce file size for the web
  3. Informative image file name
  4. ALT text for image identity

Image optimization tips are,

  1. Image size.
  2. Alt text image. Its helps for identify the image.
  3. Compress the image. Its decrease the loading time.

@Marek_5
I agree with your point of view.