Use TYPO3 7 LTS crop feature in TypoScript

headerimage.ts

lib.headerimage = COA
lib.headerimage {
    10 = FILES
    10 {
        references {
            data = levelmedia:-1, slide
            listNum = 0
        }
        renderObj = IMG_RESOURCE
        renderObj {
            file {
                import.data = file:current:publicUrl
                crop.data = file:current:crop
                maxW = 1920
                params = -quality 70
                ext = jpg
            }            
        }
    }
}