I want to change all internal links added on side bar of my blog as a image link without alt tag. It provide any link value to my articles in Google search engine.
Yes, ofcource it will provide value to your articles in the search engines as your articles, after replacing internal links with images, will become more user friendly and attractive to read. This will also help you to be more expressive through images. Thus Google will definitely give importance to your articles but it would be excellent to use alt attributes into your images as this will help you to rank your articles for images too..hope this solves your query.