Error diffusion method in a multi-level image recording apparatus utilizing adjacent-pixel characteristics

An image recording apparatus comprising:

• first signal conversion means for converting a pixel density value of a current pixel of an input image signal into a first recording control signal for defining a recording amount consisting of at least a recording width;
• second signal conversion means for converting the first recording control signal into a second recording control signal by referring to a selected adjacent pixel recording control signal for defining a recording amount of at least one adjacent pixel processed in advance and connected to said current pixel, wherein the selected adjacent pixel recording control signal places said second recording control signal closest to the first recording control signal, and said second recording control signal defines a recording amount consisting of a recording width and a recording position at which pixel formation for said current pixel is stabilized;
• recording means for recording an image based on the second recording control signal;
• and
• error diffusion means for diffusing an error between the pixel density value and a recording density value calculated based on the recording amount of the second recording control signal to a pixel density value of each pixel of said input image signal subsequent to said current pixel and located around said current pixel.

An image recording apparatus comprising:

• signal conversion means for converting a pixel density value of a current pixel of an input image signal into a recording control signal;
• recording means for recording an image based on the recording control signal;
• and
• error diffusion means for diffusing an error between the pixel density value and a recording density value based on the recording control signal to a pixel density value of each pixel of said input image signal subsequent to said current pixel and located around said current pixel, wherein
• said signal conversion means converts the pixel density value of said current pixel into a recording control signal for defining a recording width and a recording position such that at least one of a recording pattern and a non-recording pattern corresponding to said current pixel and a peripheral pixel connected to said current pixel reach a predetermined continuous value.

An image recording apparatus comprising:

• signal conversion means for converting a pixel density value of a current pixel of an input image signal into a recording control signal for defining a recording width and a recording position of said current pixel by referring to a recording control signal obtained by converting a selected pixel density value of a peripheral pixel around said current pixel to convert the pixel density value of said current pixel into the recording control signal for stably recording said current pixel;
• recording means for recording an image based on the recording control signal;
• recording density estimate means for estimating a recording density in said recording means based on the recording control signal to output a recording density estimate value to a pixel density value of each pixel located around the current pixel;
• and
• error diffusion means for diffusing an error between the pixel density value and the recording density estimate value.

An image recording method comprising the steps of:

• converting a pixel density value of a current pixel of an input image signal into a first recording control signal for defining a recording amount;
• referring to an adjacent pixel recording control signal for defining a recording amount of at least one adjacent pixel connected to said current pixel to convert the first recording control signal into a second recording control signal, the adjacent pixel recording control signal having been selected to place said second recording control signal closest to the first recording control signal, and said second recording control signal defines a recording amount at which pixel formation for said current pixel is stabilized;
• recording an image based on the second recording control signal;
• and
• diffusing an error between the pixel density value and a recording density value of the second recording control signal to a pixel density value of each pixel of said input image signal subsequent to said current pixel and located around said current pixel.

An image recording method comprising the steps of:

• converting a pixel density value of a current pixel of an input image signal into a recording control signal for defining a recording width and a recording position of said current pixel;
• recording an image based on the recording control signal;
• estimating a recording density based on the recording control signal to output a recording density estimate value by referring to a recording control signal obtained by converting a pixel density value of a peripheral pixel around said current pixel;
• and
• diffusing an error between the pixel density value and the recording density estimate value to a pixel density value of each of pixel located around the current pixel.