(i) All images compression techniques are not invertible.
(ii) Lossless compression techniques such as Runlength encoding, Huffman coding, Arithmetic coding, CAC coding, B2 coding, DPCM are invertible.
(iii) In lossless compression image is encoded by exploiting redundancies present in the image. Perfect decoding of pixel values is possible.
(iv) In lossless compression encoding and decoding is reversible process i.e. invertible.
(v) Lossy compression techniques such as JPEG, IGS Quantization are not invertible.
(vi) In lossy compression every individual pixel value or group of pixels are modified so that they can be stored with fewer bits. Due to modification exact decoding of every pixel value is not possible.
(vii) In lossy compression encoding and decoding is not reversible process i.e. not invertible.