Combining bitmaps within a memory limit

A method for combining a plurality of bitmaps to generate a resulting bitmap, the method comprising the steps of:

• A) selecting a subset of said plurality of bitmaps;
• B) extracting one or more bitmap segments from said subset of said plurality of bitmaps until memory required to store said one or more bitmap segments would exceed a first amount of memory, wherein
• said one or more bitmap segments includes bitmap segments that cover a particular range of bit positions for each bitmap in said subset of said plurality of bitmaps;
• C) generating a set of compressed interim bitmap segments based on said one or more of bitmap segments;
• and
• D) until all of said plurality of bitmaps have been selected,
• adjusting said first amount of memory based on a level of compression achieved in generating said compressed interim bitmap segments, and
• repeating steps A) through D).

A computer-readable medium carrying one or more sequences of one or more instructions for combining a plurality of bitmaps to generate a resulting bitmap, the one or more sequences of one or more instructions including instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

• A) selecting a subset of said plurality of bitmaps;
• B) extracting from said subset of said plurality of bitmaps a set of bitmap segments, wherein
• said set of bitmap segments includes bitmap segments that cover a particular range of bit positions for each bitmap in said subset of said plurality of bitmaps;
• C) generating a set of interim bitmap segments based on said set of bitmap segments;
• D) repeating steps A) through C) until either
• more than a threshold amount of memory is required to store all interim bitmap segments generated for said particular range of bit positions;
• or
• all of said plurality of bitmaps have been selected;
• and
• F) if more than said threshold amount of memory is required to store all interim bitmap segments generated for said particular range, then:
• reducing said particular range, and
• repeating steps A) through F).

A computer-readable medium carrying one or more sequences of one or more instructions for combining a plurality of bitmaps to generate a resulting bitmap, the one or more sequences of one or more instructions including instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:

• A) selecting a subset of said plurality of bitmaps;
• B) extracting one or more bitmap segments from said subset of said plurality of bitmaps until memory required to store said one or more bitmap segments would exceed a first amount of memory, wherein
• said one or more bitmap segments includes bitmap segments that cover a particular range of bit positions for each bitmap in said subset of said plurality of bitmaps;
• C) generating a set of compressed interim bitmap segments based on said one or more of bitmap segments;
• and
• D) until all of said plurality of bitmaps have been selected,
• adjusting said first amount of memory based on a level of compression achieved in generating said compressed interim
• bitmap segments, and
• repeating steps A) through D).