We know that what is the most searching keyword for Google web search. but I need most searching keyword for Google image search. It is known to us that wordtracker show us most searching keyword. My question is, Is this keyword only for web search or both for web & image search.
Try Google Insights. It has Image Search data, but unfortunately the stats are limited. Here is some other good keyword research software.
Yes I remember having that problem when using it too. I don't think there are any tools that give you actual search volume estimations. You can still get a good idea of which keywords are more popular within your niche. You just can't get a realistic prediction of how many people search images for that keyword. It does help to download the csv from Insights to see more keywords. You can cross reference multiple keywords to make results a little more accurate.