Apparatus for processing images, and method and computer program product for detecting image updates

A method of detecting an update of image information in an image processing apparatus that generates image information for displaying a screen on a terminal device connected thereto via a network and transmits the image information to the terminal device, the apparatus includes:

• a first image storage unit that stores the image information that is to be transmitted to the terminal device;
• and
• a table storage unit that stores a conversion table that is used to convert a virtual address of the first image storage unit to a physical address in units of pages defined in a storage region of the first image storage unit in correspondence with a rectangular region of a predetermined size included in the screen;
• the method comprising:
• calculating the virtual address corresponding to a pixel included in the rectangular region;
• acquiring the physical address corresponding to the virtual address calculated for each pixel of the image information for which writing is requested, based on the conversion table stored in the table storage unit;
• writing the image information for which the writing is requested into the acquired physical address;
• and
• detecting in units of the pages, an updated portion of the image information that is a portion in which the image information does not match before and after the writing.

A computer program product having a non-transitory computer readable medium including program instructions stored therein for detecting an update of image information in an image processing apparatus that generates image information for displaying a screen on a terminal device connected thereto via a network and transmits the image information to the terminal device, the apparatus includes:

• a first image storage unit that stores the image information that is to be transmitted to the terminal device;
• and
• a table storage unit that stores a conversion table that is used to convert a virtual address of the first image storage unit to a physical address in units of pages defined in a storage region of the first image storage unit in correspondence with a rectangular region of a predetermined size included in the screen,
• wherein the instructions, when executed by a computer, cause the computer to perform steps comprising:
• calculating the virtual address corresponding to a pixel included in the rectangular region;
• acquiring the physical address corresponding to the virtual address calculated for each pixel of the image information for which writing is requested, based on the conversion table stored in the table storage unit;
• writing the image information for which the writing is requested into the acquired physical address;
• and
• detecting in units of the pages, an updated portion of the image information that is a portion in which the image information does not match before and after the writing.