local sprite=app.open(app.params.source)
local height=tonumber(app.params.height or '112')
sprite:crop(Rectangle(400,170,1272,math.floor(1272*height/640+0.5)))
app.command.SpriteSize{ui=false,width=640,height=height,method='nearest-neighbor'}
sprite:saveAs(app.params.output)
sprite:close()