An image encoding apparatus having a transmission side capable of preventing generation of pseudo−synchronization and a reception side capable of restoring an image as intended at the transmission side. In the image encoding apparatus; a synchronous word containing possibility detection unit (212) decides whether a quantized DCT coefficient can be a bit string to become a synchronous word. When the possibility is detected, a control signal is output to an image information modification unit (213). Upon reception of the control signal, the image information modification unit (213) modifies image information (quantized DCT coefficient), is output to a variable length encoding unit (208), and output to a reverse quantization unit (209). When the possibility of containing a synchronous word is not detected, the quantized DCT coefficient is output to the variable length encoding unit (208) and output to the reverse quantization unit (209).
IMAGE ENCODING APPARATUS AND IMAGE ENCODING METHOD