1. A method for prediction coding using scalable video codec, the method comprising: setting a target layer of an image, by a server, based on information about a device, if a service of the image is requested by the device; performing, by a server, a chrominance space conversion on an image signal of a base layer of the image using a chrominance space conversion equation preset in a scalable video codec selectively according to whether the chrominance space conversion is required in inter-layer prediction coding between the base layer and the target layer; and performing, by a server, the inter-layer prediction coding through an additional signal conversion based on necessary any one of spatial scalability, chroma-format scalability and bit-depth scalability wherein the chrominance space conversion equation is the following equation, ( Y ⁢ ⁢ 1 Y ⁢ ⁢ 2 Y ⁢ ⁢ 3 ) = ( K 1 K 2 K 3 K 4 K 5 K 6 K 7 K 8 K 9 ) × ( X ⁢ ⁢ 1 - a 1 X ⁢ ⁢ 2 - a 2 X ⁢ ⁢ 3 - a 3 ) where the (Y1, Y2, Y3) is a chrominance space and (X1, X2, X3) is another chrominance space, wherein the K1 to K9 and a1 to a3 coefficients are integer coefficients to which image parameter coefficients of a Video Usability Information (VUI) of a Sequence Parameter Set (SPS) or a Picture Parameter Set (PPS) in an information area of a video stream of the base layer are integerized.