Method for maintaining bit density while converting images in scale or resolution

A method for increasing resolution of an input image in an input bitmap while performing a density preserving smoothing operation, the input bitmap including a first set of pixels residing in a memory, said method comprising the steps of:

• mapping the first set of pixels into a second set of individual pixels, each of the individual pixels of the second set having a value selected from a first set of output states, each of the output states corresponding with a level of discretized information;
• developing pixel arrays from the second set of individual pixels, the pixel arrays respectively representing local neighborhoods for the individual pixels of the second set, each of the local neighborhoods having a value selected from a second set of output states, each of the output states of the second set of output states corresponding with a level of discretized information;
• combining the output state of each individual pixel with the output state of its respective local neighborhood resulting in a selected one of a third set of output states based on a predetermined relationship between the first and second sets of output states, each of the output states of the third set of output states corresponding with a level of discretized information, the selected one of the third set of output states reflecting a current output state of a selected individual pixel and a preference of the selected individual pixel for a selected one of the output states of the first set of output states, at least one of the third set of output states having at least one counterpart in the third set of output states;
• and
• examining the individual pixels within a preselected area to locate a preselected number of individual pixels including a first individual pixel having a selected one of the third set of output states and at least a second pixel having a counterpart value to the first individual pixel having the selected one of the third set of output states;
• and
• altering the respective output states of the first and second individual pixels when the first and second individual pixels are within the preselected area wherein the resolution of the output image is changed and the output image is smoothed without altering the density of the output image relative to the input image.

A method for increasing resolution of an input image in an input bitmap while performing a density preserving smoothing operation, the input bitmap including a first set of pixels residing in a memory, said method comprising the steps of:

• mapping the first set of pixels into a second set of individual pixels, each of the individual pixels of the second set having a value selected from a first set of two output states, each of the output states corresponding with a level of discretized information;
• developing pixel arrays from the second set of individual pixels, the pixel arrays respectively representing local neighborhoods for the individual pixels of the second set, each of the local neighborhoods having a value selected from a second set of two output states, each of the output states of the second set of output states corresponding with a level of discretized information;
• comparing the output state of each individual pixel with the output state of its respective local neighborhood, the comparing step resulting in a selected one of values based on a predetermined relationship between the first and second sets of output states, each of the four values corresponding with a level of discretized information, the selected one of the four values reflecting a current output state of a selected individual pixel and a preference of the selected individual pixel for one of the first set of output states, at least one of the four values having at least one counterpart in the set of four values;
• examining the individual pixels within a predetermined area to locate a pair of individual pixels including a first individual pixel having a selected one of the four values and a second pixel having a counterpart value to the first individual pixel having the selected one of the four values;
• pairing the first and second individual pixels when the first and second pixels are within a predetermined distance of one another;
• and
• altering the respective output states of the first and second individual pixels when the first and second individual pixels are within the preselected area wherein the resolution of the output image is changed and the output image is smoothed without altering the density of the output image relative to the input image.