Font compression method and apparatus

A font compression apparatus for compressing a first type font of characters and figures arranged in an XY matrix into a second type font of the same characters and figures, arranged in a second matrix by dropping predetermined dots in at least one of the column and row directions of the XY dot matrix, comprising:

• (a) a keyboard;
• (b) a front memory for storing said first type font inputted from said keyboard;
• (c) a central processing unit (CPU) for receiving and processing information associated with the first type font sorted in said font memory;
• and
• (d) a control memory, coupled to said CPU, for storing predetermined control instructions for said CPU, whereby the first type font which has been inputted from the keyboard and stored in said font memory is processed by said CPU in response to the control instructions stored in said control memory and is automatically converted into the second type font which is required by a peripheral device, wherein said CPU includes means for dividing said XY dot matrix into a plurality of sections comprising a predetermined number of bit positions along said at least one of said column and row directions;
• means for comparing information bits existing in at least two bit positions of one of said sections and a first bit position in an adjacent next section;
• and means for dropping at least one information bit in a specified bit position in said one section in accordance with the result of the comparison and extracting the remaining information bits in said one section as compressed information bits.

A method of compressing each character of a font represented by series of dots in a matrix, comprising the steps of:

• (a) partitioning said series of dots into a plurality of lateral bit groups equal to the number of bits to be deleted with respect to the row direction;
• (b) adding one dummy column to the last column of said matrix;
• (c) examining each lateral bit group to determine which dot should be deleted from the constituent bits of the lateral group by finding one pair of adjacent bits of like value;
• (d) deleting dots from each row in accordance with the results of said examining step;
• (e) dividing said series of dots into a plurality of vertical bit groups equal to the number of bits to be deleted with respect to the column direction;
• (f) joining one dummy row subsequent to the last row of said matrix;
• (g) examining each of the vertical bit group for determining what dot should be deleted from the constituent bits of the vertical group by finding one pair of adjacent value bits of like value;
• (h) deleting dots from each column in accordance with the results of said examining step;
• wherein the determination as to whether a dot is to be deleted from each group takes into account the immediately adjacent bit that belongs to said dummy row or column, or a group adjacent to said subjected to the determination, amd whether said end bit has the same value as said adjacent bit.