scale a taken photo to screen size - lua

Question

I can take a photo using this code :
local centerX = display.contentCenterX
local centerY = display.contentCenterY
local isXcodeSimulator = "iPhone Simulator" == system.getInfo("model")
if (isXcodeSimulator) then
local alert = native.showAlert( "Information", "Camera API not available on iOS Simulator.", { "OK"})
end
local sessionComplete = function(event)
local image = event.target
if image then
image.x = centerX
image.y = centerY
local w = image.width
local h = image.height
end
end
local listener = function( event )
if media.hasSource( media.Camera ) then
media.capturePhoto( { listener = sessionComplete } )
else
native.showAlert("Corona", "Camera not found.")
end
return true
end
trigger:addEventListener( "tap", listener )
But if the picture is to big it doesn't zoom out or scale down, i have tried local w =display.contentWidth but nothing's happening. How can i scale the photo to the exact screen size, probably need to scale in the Y axis to fill the screen

Answer 1

If you simply wish to scale the picture down there are two ways you can do that.
1: Use scale on the display object (http://docs.coronalabs.com/api/type/DisplayObject/scale.html)
object:scale(xScale, yScale)
or the second solution which I suspect is what you are looking for
2: Set the image size directly.
Set the image width/height using object.width and object.height and setting the respective contentWidth and ContentHeight of your display object.
Change the sessionComplete function to the following
local sessionComplete = function(event)
local image = event.target
if image then
image.x = centerX
image.y = centerY
image.width = display.contentWidth
image.height = display.contentHeight
end
end

Answer 2

Solved the problem by using this equation
image.contentWidth / image.contentHeight * display.contentHeight
local sessionComplete = function(event)
local image = event.target
if image then
imgWidth = image.contentWidth / image.contentHeight * display.contentHeight
image.x = centerX
image.y = centerY
image.width = imgWidth
image.height = display.contentHeight
end
end