Image forming apparatus and method for controlling image forming apparatus

An image forming apparatus comprising:

• density correcting means for executing a gamma correction for a density of an input image using a gamma correction value;
• forming means for forming the image obtained by said density correcting means executing the gamma correction on the input image, on a sheet;
• changing means for changing the gamma correction value used by said density correcting means;
• and
• notifying means for notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when said changing means changes the gamma correction value by an amount equal to or greater than a predetermined amount.

An image forming apparatus comprising:

• intermediate forming means for executing a gamma correction for a density of an input image using a gamma correction value, binarizing the image obtained by executing the gamma correction on the input image, and forming the binarized image obtained by the binarization on a intermediate transfer body;
• measurement means for measuring a density of the binarized image formed by said intermediate forming means;
• final forming means for forming the binarized image formed on the intermediate transfer body on a sheet;
• measurement result obtaining means for inputting an image used for adjusting the gamma correction value into said intermediate forming means so that said intermediate forming means forms the binarized image on the intermediate transfer body, and causing said measurement means to measure a density of the binarized image formed on the intermediate transfer body to obtain a measurement result;
• adjustment means for adjusting the gamma correction value based on the measurement result obtained by said measurement result obtaining means;
• and
• notifying means for notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when the measurement result obtained by said measurement result obtaining means differs from a measurement result obtained just prior to the previous density adjustment for the copy-forgery-inhibited pattern image by an amount equal to or greater than a predetermined amount.

A control method of an image forming apparatus, said method comprising:

• a density correcting step of correcting densities of respective pixels of an input image using a density correcting parameter;
• a forming step of forming an image, in which densities of respective pixels of the input image have been corrected by said density correcting step, on a sheet;
• a changing step of changing a density correcting parameter used in said density correcting step;
• and
• a notifying step of notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when said changing means changes the density correcting parameter by an amount equal to or greater than a predetermined amount.

A control method of an image forming apparatus, said method comprising:

• a density correcting step of executing a gamma correction for a density of an input image using a gamma correction value;
• a forming step of forming the image obtained by executing the gamma correction in said density correcting step, on a sheet;
• a changing step of changing the gamma correction value used in said density correcting step;
• and
• a notifying step of notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when said changing step changes the gamma correction value by an amount equal to or greater than a predetermined amount.

A control method of an image forming apparatus, said method comprising:

• an intermediate forming step of executing a gamma correction for a density of an input image using a gamma correction value, binarizing the image obtained by executing the gamma correction, and forming the binarized image obtained by the binarization on a intermediate transfer body;
• a measurement step of measuring a density of the binarized image formed in said intermediate forming step;
• a final forming step of forming the binarized image formed on the intermediate transfer body on a sheet;
• a measurement result obtaining step of inputting an image used for adjusting the gamma correction value in said intermediate forming step so that said intermediate forming step forms the binarized image on the intermediate transfer body, and causing said measurement step to measure a density of the binarized image formed on the intermediate transfer body to obtain a measurement result;
• an adjustment step of adjusting the gamma correction value based on the measurement result obtained by said measurement result obtaining step;
• and
• a notifying step of notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when the measurement result obtained by said measurement result obtaining step differs from a measurement result obtained just before a previous density adjustment for the copy-forgery-inhibited pattern image by an amount equal to or greater than a predetermined amount.

A storage medium storing a program readably by a computer, said program being of a control process of an image forming apparatus, said process comprising:

• a density correcting step of correcting densities of respective pixels of an input image using a density correcting parameter;
• a forming step of forming an image, in which densities of respective pixels have been corrected by said density correcting step, on a sheet;
• a changing step of changing a density correcting parameter used in said density correcting step;
• and
• a notifying step of notifying a user to execute a density adjustment for a copy-forgery-inhibited pattern image, when said changing means changes the density correcting parameter by an amount equal to or greater than a predetermined amount.