Image processing apparatus

An image processing apparatus in which image data is compressed and stored and the compressed and stored image data is expanded so as to be output to a printer, said apparatus comprising:

• a central processing unit;
• a system bus connected to said central processing unit;
• a first local bus;
• a bus bridge for connecting said system bus and said first local bus to each other;
• a second local bus;
• separating means for connecting/separating said first and second local buses to/from each other in response to a control signal;
• a buffer memory connected to said second local bus for storing data to be compressed/expanded which is sent from said first local bus through said second local bus and said separating means;
• a compressing/expanding section respectively to said first and second local buses for receiving the data read out of said buffer memory through said second local bus and compressing/expanded data so as to output the compressed/expanded data to said first local bus;
• and
• control means connected to said first local bus for outputting to said separating means the control signal for connecting/separating said first and second local buses to/from each other in response to a command sent from said central processing unit through said system bus and said bus bridge and for controlling data reading from said buffer memory to said second local bus in a state that said first and second local buses are separated from each other.