Resolution conversion module, printer driver with resolution conversion module, and image resolution conversion method

• US 6,333,792 B1
• Filed: 02/27/1998
• Issued: 12/25/2001
• Est. Priority Date: 02/28/1997
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kimura, Takeo
• Primary Examiner(s): Coles, Edward
• Assistant Examiner(s): HASKINS, TWYLER LAMB
• Application Number:
  US09/031,969
• Time in Patent Office: 1,397 Days
• Field of Search: 382/268, 382/269, 382/237, 382/258, 382/299, 358/401, 358/458, 358/451, 358/1.1, 358/447, 358/1.2, 358/450
• US Class Current: 358/1.2
• CPC Class Codes: G06F 3/1204 resulting in reduced user or operator actions, e.g. presetting, automatic actions, using hardware token storing data
• CPC Class Codes: G06F 3/1208 resulting in improved quality of the output result, e.g. print layout, colours, workflows, print preview
• CPC Class Codes: G06F 3/1225 Software update, e.g. print driver, modules, plug-ins, fonts
• CPC Class Codes: G06F 3/1244 Job translation or job parsing, e.g. page banding
• CPC Class Codes: G06F 3/1284 Local printer device
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: H04N 1/3875 combined with enlarging or reducing enlarging or reducing per se H04N1/393

Abstract

An image resolution conversion method which can cope with arbitrary magnifications including non-integer magnifications with simple operation and sequence, has an identical interface, and can be efficiently installed in a printer driver, and a resolution conversion module that implements the method. The resolution conversion module receives information representing the resolutions before and after conversion from an image processing program, and calculates the magnification or reduction value for each pixel of an original image before conversion on the basis of the received information. The module receives information of a processing region, which is segmented with reference to the image size after conversion, from the image processing program, and obtains that region on the original image before conversion, which corresponds to the segmented processing region, on the basis of the magnification or reduction values for pixels. The module passes the information of the obtained region of the original image to the image processing program, and requests the image processing program to transfer original image data. The module changes the size of the original image data of the obtained region on the original image received from the image processing program on the basis of the magnification or reduction values for pixels for each region, and passes the data after resolution conversion of the region to the image processing program.

Claims

1. A resolution conversion module for converting a resolution of image data, comprising the steps of:

receiving information representing resolutions before and after conversion from a printer driver;

calculating a magnification or reduction value for each pixel of an original image before conversion on the basis of the received information;

receiving information of a processing region, which is segmented with reference to an image size after conversion, from the printer driver;

obtaining a region on the original image before conversion corresponding to the segmented processing region on the basis of the magnification or reduction values for pixels;

passing information of the obtained region on the original image before conversion to the printer driver;

receiving original image data of the obtained region from the printer driver;

changing a size of the received original image data on the basis of the magnification or reduction values for pixels; and

passing the data of the region after resolution conversion to the printer driver.

2. The module according to claim 1, wherein the information representing the resolutions before and after conversion represents sizes of image data before and after conversion, which are expressed by the numbers of pixels.

3. The module according to claim 1, wherein the magnification or reduction values for the pixels of the original image before conversion include a combination of an integer multiple or a fraction of an integer so that a sum of magnification or reduction values for a plurality of pixel yield magnification of the resolutions before and after conversion.

4. The module according to claim 1, wherein the information of the segmented processing region includes a start point position and size of the region.

5. The module according to claim 4, wherein the step of obtaining the region on the original image includes the steps of:

adjusting the start point and size using the number of pixels required for resolution conversion; and

adjusting the start point and size of the region in consideration of end portions of the original image.

6. The module according to claim 1, wherein the information of the obtained region on the original image includes a start point position and size of the region.

7. The module according to claim 1, wherein the step of changing the size of the image includes the steps of:

receiving image data in units of lines;

holding the received image data in correspondence with the number of lines required for changing the size;

discarding image data for the line which has become unnecessary and updating the image data to image data for a new line; and

outputting processed data in units of lines.

8. A resolution conversion module which is installed in printer driver when it is used, and converts a resolution of image data, comprising the steps of:

receiving information representing resolutions before and after conversion from the printer driver;

calculating a magnification or reduction value for each pixel of an original image before conversion on the basis of the received information;

receiving information of a processing region, which is segmented with reference to an image size after conversion, from the printer driver;

obtaining a region on the original image before conversion corresponding to the segmented processing region on the basis of the magnification or reduction values for pixels;

passing information of the obtained region on the original image to the printer driver, requesting the printer driver to transfer original image data, and receiving the original image data of the obtained region therefrom;

changing a size of an image on the basis of the magnification or reduction values for pixels for each obtained region on the original image; and

requesting the printer driver to take size-changed data, and passing the data of the region after resolution conversion,

wherein the resolution after conversion is the resolution of a printer, and the processing region which is segmented with reference to the image size after conversion is a band region.

9. The module according to claim 8, wherein the information representing the resolutions before and after conversion represents sizes of image data before and after conversion, which are expressed by the numbers of pixels.

10. The module according to claim 8, wherein the magnification or reduction values for the pixels of the original image before conversion include a combination f an integer multiple or a fraction of an integer so that a sum of magnification or reduction values for a plurality of pixel yield magnification of the resolutions before and after conversion.

11. The module according to claim 8, wherein the information of the segmented processing region includes a start point position and size of the region.

12. The module according to claim 11, wherein the step of obtaining the region on the original image includes the steps of:

adjusting the start point and size using the number of pixels required for resolution conversion; and

adjusting the start point and size of the region in consideration of end portions of the original image.

13. The module according to claim 8, wherein the information of the obtained region on the original image includes a start point position and size of the region.

14. The module according to claim 8, wherein the step of changing the size of the image includes the steps of:

receiving image data in units of lines;

holding the received image data in correspondence with the number of lines required for changing the size;

discarding image data for the line which has become unnecessary and updating the image data to image data for a new line; and

outputting processed data in units of lines.

15. A printer driver installed with a resolution conversion module for image data,

said resolution conversion module comprising the steps of:

receiving information representing resolutions before and after conversion from said driver;

calculating a magnification or reduction value for each pixel of an original image before conversion on the basis of the received information;

receiving information of a processing region, which is segmented with reference to an image size after conversion, from said driver;

obtaining a region on the original image before conversion corresponding to the segmented processing region on the basis of the magnification or reduction values for pixels;

passing information of the obtained region on the original image to said driver, requesting said driver to transfer original image data, and receiving the original image data of the obtained region therefrom;

changing a size of an image on the basis of the magnification or reduction values for pixels for each obtained region on the original image; and

requesting said driver to take size-changed data, and passing the data of the region after resolution conversion.

16. The driver according to claim 15, wherein the information representing the resolutions before and after conversion represents sizes of image data before and after conversion, which are expressed by the numbers of pixels.

17. An image resolution conversion method for converting a resolution of image data, wherein when there are a resolution conversion module for performing resolution conversion and a printer driver that requires resolution conversion of image data, information representing resolutions before and after conversion and information of a processing region segmented with reference to an image size after conversion are passed from said printer driver to said resolution conversion module,

said resolution conversion module calculates a magnification or reduction value for each pixel of an original image before conversion on the basis of the information representing the resolutions before and after conversion, obtains a region on the original image before conversion corresponding to the segmented processing region on the basis of the magnification or reduction values for pixels, passes the information of the obtained region to said printer driver, and requests said printer driver to transfer original image data of the region on the original image, and when the original image data of the region is passed from said printer driver to said resolution conversion program, said resolution conversion program changes a size of an image on the basis of the magnifications or reduction values for pixels for each obtained region on the original image, and sends back size-changed image data to said printer driver.

18. The method according to claim 17, wherein the information representing the resolutions before and after conversion represents sizes of image data before and after conversion, which are expressed by the numbers of pixels.

19. The method according to claim 17, wherein when the region on the original image is obtained, a start point and size are adjusted using the number of pixels required for resolution conversion, and a start point and size of the region are adjusted in consideration of end portions of the original image.

20. A computer readable memory that stores a program for converting a resolution of image data, having

a resolution conversion module for converting the resolution, and a printer driver with said resolution conversion module,

said resolution conversion module comprising:

a magnification generation module for calculating a magnification or reduction value for each pixel of an original image before conversion on the basis of information representing resolutions before and after conversion;

a corresponding region calculation module for calculating a region on the original image before conversion corresponding to a processing region, which is segmented with reference to an image size after conversion, on the basis of the magnification or reduction values for pixels;

a size change processing module for changing a size of original image data of the calculated region on the basis of the magnification or reduction values for pixels; and

an interface module for receiving the information representing the resolutions before and after conversion, the information of the segmented processing region, and the original image data of the calculated region from said printer driver, and passing the information of the calculated region and data after resolution conversion of the segmented region to said printer driver.