in Corona and Lua - how do I completely remove a display object (an image) from the screen and also from memory

I am trying to fix my memory leak in Lua.
To test, I am creating 100,000 images on screen and recording them.
Then I remove them from the display. This works.
The problem is that the memory used never reduces back to that before the creation.
Here is my code:

local _storeContents = {}
local function OnDebugTest( event )
    for i = 1, 100000, 1 do
        img = display.newImage( "planet1.png", math.random()*400, math.random()*400-200 )
        _group:insert(img)
        table.insert(_storeContents,img)
    end

    for a,b in pairs(_storeContents) do
        display.remove(b)
    end

    _storeContents = {}
end

I am using gcinfo() to get the memory usage.
What do I need to do to fix the memory leak?
jasonbbSoftware EngineerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

jasonbbSoftware EngineerAuthor Commented:
I think the code is working and is releasing the memory.
I made this change to the code:
    for a,b in pairs(_storeContents) do
        display.remove(b)
        _storeContents [a] = nil
    end
and I use this later, called from a button:
    collectgarbage()
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Game Programming

From novice to tech pro — start learning today.