During my visit to many blogs , I found that many of them have not optimized the pictures on their blog. So I am writing this , it is very easy and helps to get higher search engine ranking.
This is for blogspot users.
When you create a new post or edit a existing post , above post body , you find a chain like symbol called 'Insert link' or Link. You have to select the picture with single mouse click and then click insert link icon , it will ask you to enter http:// .Here you have to enter your blog URL i.e. yourname.blogspot.com.
After this click on 'Edit html' above post body , located beside compose.
You will find alt " " .You need to enter your keyword in the quotes i.e. alt"keyword"
Now you can publish your post , check your picture by clicking on it and by pointing mouse on it.
Your picture optimization is done. You can also rename your jpg file to your-keyword.jpg.
Please do not optimize all old images on your blog at a time .
Please also check from where you are loading images (picture url) and file size of picture in kilobytes ,because some times due to this your blog gets loaded slowly.You can reduce file size using softwares like Photoshop.
I have also done keyword optimization by text link optimization , in this post .Find out those and leave a comment here.