thanks wiz and erthling 
 
erthling: the blue tint is achieved by inverting the red and blue colour channels under 'Channel Mixer' i.e. under red channel assign red to 0 and blue to 100 and under blue channel assign blue to 0 and red to 100. this processing is predominantly used for digital infra-red pictures to convert the sky colour to blue
 
haven't visited the exhibition, the daily travelling from school to my dorm is really tiring, too often don't feel like going out at all
 
030706 - local carpenter
		
		
	
	
		
	
				
			erthling: the blue tint is achieved by inverting the red and blue colour channels under 'Channel Mixer' i.e. under red channel assign red to 0 and blue to 100 and under blue channel assign blue to 0 and red to 100. this processing is predominantly used for digital infra-red pictures to convert the sky colour to blue
haven't visited the exhibition, the daily travelling from school to my dorm is really tiring, too often don't feel like going out at all
030706 - local carpenter