Color image processing apparatus using pulse width modulation

A color image processing apparatus using a gradation image recording method by pulse width modulation, comprising:

• first path image output means for outputting a patch image to determine a pulse width selection table for the pulse width modulation;
• first fetching means for fetching patch image data by reading the patch image output from the first patch image output means;
• pulse width selection table determining means for determining the pulse width selection table based on the patch image data given from the first fetching means;
• color image processing means for processing and outputting a given color image signal based on the pulse width selection table determined by the pulse width selection table determining means;
• second patch image output means for outputting a second patch image to determine a gradation correction table based on the pulse width selection tale determined by the pulse width selection table determining means;
• second fetching means for fetching second patch image data by reading the second patch image output from the second patch image output means;
• gradation correction table determining means for determining a gradation correction table based on the second patch image data given from the second fetching means;
• and
• color image processing means for processing and outputting a given color image signal based on the gradation correction table determined by the gradation correction table determining means and the pulse width selection table determined by the pulse width selection table determining means.

A color image processing apparatus using a gradation image recording method by pulse width modulation, comprising:

• first path image output means for outputting a patch image to determine a pulse width selection table for the pulse width modulation;
• first fetching means for fetching patch image data by reading the patch image output from the first patch image output means;
• pulse width selection table determining means for determining the pulse width selection table based on the patch image data given from the first fetching means;
• color image processing means for processing and outputting a given color image signal based on the pulse width selection table determined by the pulse width selection table determining means;
• second patch image output means for outputting a second patch image to determine a gradation correction table based on the pulse width selection to be determined by the pulse width selection table determining means;
• second fetching means for fetching second patch image data by reading the second patch image output from the second patch image output means;
• gradation correction table determining means for determining a gradation correction table based on the second patch image data given from the second fetching means;
• third patch image output means for outputting a third patch image to determine a color conversion table for the color conversion based on the gradation correction table and the pulse width selection table;
• color correction table determining means for determining the color correction table based on patch image data reading the third patch image output by the third patch image output means;
• and
• means for processing and outputting a given color image signal based on the color correction table determined by the color correction table determining means and the pulse width selection table determined by the pulse width selection table determining means.

A color image processing apparatus using a gradation image recording method by pulse width modulation, comprising:

• path image output means for outputting a patch image to determine a pulse width selection table for the pulse width modulation;
• fetching means for fetching patch image data by reading the patch image output from the patch image output means;
• pulse width selection table determining means for determining the pulse width selection table based on the patch image data given from the fetching means;
• color image processing means for processing and outputting a given color image signal based on the pulse width selection table determined by the pulse width selection table determining means;
• wherein the pulse width selection table determining means includes:
• pre-processing means for receiving the patch image output from the patch image output means, thereby performing a pre-process of shading correction or γ correction by setting which is different from normal image formation;
• pulse width selection table determining means for determining the pulse width selection table based on the patch image data subjected to the pre-process by the pre-processing means;
• and
• means for processing and outputting a given color image signal based on the pulse width selection table determined by the pulse width selection table determining means.

A color image processing apparatus using a gradation image recording method by pulse width modulation, comprising:

• color converting means for performing color conversion for a given color image;
• gradation correction means for correcting a gradation for each color channel for the color image subjected to the color conversion by the color converting means;
• pulse width selecting means for selecting a pulse width for each color channel for the color image subjected to the gradation correction by the gradation correcting means;
• and
• color image processing means for processing and outputting the color image based on a pulse width selected by the pulse width selecting means.

A color image processing method using gradation image recording by pulse width modulation, the method comprising:

• determining a pulse width selection table for pulse width modulation;
• determining a gradation correction table based on the determined pulse width selection table;
• determining a color conversion table based on the determined gradation correction table;
• and
• correcting a given color image signal and outputting the corrected color image signal based on the determined color conversion table, the determined gradation correction table, and the determined pulse width selection table.

A color image processing method using gradation image recording by pulse width modulation, the method comprising:

• performing color conversion for a given color image;
• correcting a gradation for each color channel for the color image subjected to the color conversion;
• selecting a pulse width for each color channel for the color image subjected to the gradation correction;
• and
• processing and outputting the color image based on the selected pulse width.