Image scaling for images including low resolution text

• US 9,536,281 B2
• Filed: 04/17/2014
• Issued: 01/03/2017
• Est. Priority Date: 05/24/2013
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Moffatt, Edwin P. J., Staddon, Luke P.
• Primary Examiner(s): Harrison, Chante
• Application Number:
  US14/255,466
• Publication Number:
  US 20140347399A1
• Time in Patent Office: 992 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403

Abstract

A method and system are provided for image scaling including low resolution text areas. The method may include: determining one or more areas of text in an image to be scaled; scaling the one or more areas of text using two or more scaling algorithms to a required resolution to acquire two or more scaled versions of the text area; selecting the clearest text in a text area from two or more scaled versions of the text area; scaling the overall image to the required resolution; and merging the scaled overall image with the selected scaled version of each text area.

Claims

1. A method for image scaling including low resolution text areas, the method comprising:

determining, by one or more processors, one or more areas of text in an image to be scaled for display on a screen;

scaling, by one or more processors, the one or more areas of text using two or more scaling algorithms to a required resolution to acquire two or more scaled versions of the text area;

selecting a clearest text in a text area from two or more scaled versions of the text area to create an overall image;

removing, by one or more processors, one or more identified text areas from the overall image displayed on the screen;

filling in, by one or more processors, the removed one or more identified text areas with an image matching a background area surrounding an area from which the identified text is removed;

marking, by one or more processors, an area of the removed one or more identified text areas with a distinguishing color before filling with a matching overall image;

scaling, by one or more processors, the overall image to the required resolution;

applying, by one or more processors, shaders to a scaled overall image prior to merging the scaled overall image with selected versions of each text area;

merging, by one or more processors, the scaled overall image with the selected scaled version of each text area to create a merged image; and

displaying, by one or more processors, the merged image on the screen.

2. The method as claimed in claim 1, wherein one of the scaling algorithms is a linear algorithm for scaling the original text.

3. The method as claimed in claim 1, further comprising:

selecting the clearest text by comparing, by one or more processors, the two or more scaled versions of the text area using a text-recognition algorithm to provide a metric of the clarity of the text in the text area.

4. The method as claimed in claim 1, wherein determining one or more text areas in an image to be scaled comprises:

applying, by one or more processors, text-recognition to identify a text area; and

drawing, by one or more processors, a bounding box around a text area.

5. The method as claimed in claim 1, wherein determining one or more text areas in an image to be scaled includes:

applying, by one or more processors, rules of known characteristics of text areas of an image to identify a text area.

6. The method as claimed in claim 1, wherein two or more different scaling algorithms are used for the group consisting of:

each text area and the overall image.

7. The method as claimed in claim 1, wherein said removing and filling are carried out on the pre-scaled overall image.

8. The method as claimed in claim 1, wherein merging the scaled overall image with the selected one or more text areas includes:

replacing by one or more processors, pixels in the overall with any non-alpha pixels in the text areas.

9. The method as claimed in claim 1, wherein scaling the overall image to the required resolution includes scaling the original text areas with the overall image, and wherein merging the scaled overall image with the selected version of each text area includes overwriting the scaled text areas with the selected scaled version of each text area.

10. The method as claimed in claim 1, further comprising:

applying by one or more processors, shaders to the scaled overall image prior to merging the scaled overall image with the selected versions of each text area.

11. The method as claimed in claim 1, further comprising:

preserving, by one or more processors, offsets of text areas in the image in order to merge the scaled text areas with the scaled overall image.

12. A computer system comprising one or more processors, one or more computer readable memories, one or more computer readable storage mediums, wherein said one or more computer readable storage mediums are not transitory signals per se, and program instructions stored on at least one of the one or more storage mediums for execution by at least one of the one or more processors via at least one of the one or more memories, the stored program instructions comprising:

program instructions to determine one or more areas of text in an image to be scaled for display on a screen;

program instructions to scale the one or more areas of text using two or more scaling algorithms to a required resolution to acquire two or more scaled versions of the text area;

program instructions to select a clearest text in a text area from two or more scaled versions of the text area;

program instructions to remove one or more identified text areas from the overall image displayed on the screen;

program instructions to fill in the removed one or more identified text areas with an image matching a background area surrounding an area from which the identified text is removed;

program instructions to mark an area of the removed one or more identified text areas with a distinguishing color before filling with a matching overall image;

program instructions to scale the overall image to the required resolution;

program instructions to apply shaders to a scaled overall image prior to merging the scaled overall image with selected versions of each text area;

program instructions to merge the scaled overall image with the selected scaled version of each text areas to create a merged image; and

program instructions to display the merged image on a screen.

13. The system as claimed in claim 12, wherein one of the scaling algorithms is a linear algorithm for scaling the original text.

14. The system as claimed in claim 12, further comprising:

program instructions to apply text-recognition to identify a text area; and

program instructions to draw a bounding box around a text area.

15. A computer program product for image scaling including low resolution text areas, the computer program product comprising a non-transitory computer readable storage medium having program code embodied therewith, the program code readable and executable by a processor to perform a method comprising:

determining one or more areas of text in an image to be scaled;

scaling the one or more areas of text using two or more scaling algorithms to a required resolution to acquire two or more scaled versions of the text area;

selecting a clearest text in a text area from two or more scaled versions of the text area;

removing one or more identified text areas from the overall image displayed on the screen;

filling in the removed one or more identified text areas with an image matching a background area surrounding an area from which the identified text is removed,

marking an area of the removed one or more identified text areas with a distinguishing color before filling with a matching overall image;

scaling the overall image to the required resolution;

applying shaders to a scaled overall image prior to merging the scaled overall image with selected versions of each text area;

merging the scaled overall image with the selected scaled version of each text area to create a merged image; and

displaying the merged image on a screen.

16. The computer program product as claimed in claim 15, wherein one of the scaling algorithms is a linear algorithm for scaling the original text.

17. The computer program product as claimed in claim 15, wherein the method further comprises:

selecting the clearest text by comparing the two or more scaled versions of the text area using a text-recognition algorithm to provide a metric of the clarity of the text in the text area.