Device and method for processing digital images captured by a binary image sensor

1. A method for processing image data, said method comprising determining a set of parameters based on a binary digital image such that said set of parameters comprises information about the density of white and/or black pixels of a first group of pixels of said binary digital image, and information about the density of white and/or black pixels of a second group of pixels of said binary digital image, the information for each of the first group and the second group representing binary image data as continuous tone imagery;

wherein said set of parameters comprises information about the distribution of white and/or black pixels in said first group of pixels, and information about the distribution of white and/or black pixels in said second group of pixels; and

wherein said set of parameters is arranged in one or more parameter arrays, and the elements of parameter arrays associated with consecutive input images are aligned so as to compensate movement between the consecutive images.

2. The method of claim 1 wherein data size of said binary input image is greater than or equal to 4 times the total data size of said set of parameters.

3. The method of claim 2 wherein data size of said binary input image is greater than or equal to 100 times the total data size of said set of parameters.

4. The method according to claim 1 further comprising capturing said binary digital image by a binary image sensor and imaging optics.

5. The method of claim 4 wherein individual detectors of said binary image sensor are smaller than a minimum focal spot of said imaging optics.

6. The method according to claim 4 wherein estimated movement between consecutive images is compensated by moving the position of a read-out window with respect to detectors of the image sensor.

7. The method according to claim 4 wherein an exposure time of said binary input image is set based on an optical exposure of a previously captured image.

8. The method according to claim 1 further comprising averaging parameters generated from two or more binary digital images.

9. The method according to claim 8 wherein the number of binary digital images used for said averaging is determined based on a detected optical exposure.

10. The method according to claim 1 wherein the distance between adjacent groups of pixels depends on the density of white or black input pixels within a portion of an image.

11. A non-transitory computer readable medium comprising program code, which when executed by a data processor is for determining a set of parameters based on a binary digital image such that said set of parameters comprises information about the density of white and/or black pixels of a first group of pixels of said binary digital image, and information about the density of white and/or black pixels of a second group of pixels of said binary digital image, the information for each of the first group and the second group representing binary image data as continuous tone imagery;

wherein said set of parameters comprises information about the distribution of white and/or black pixels in said first group of pixels, and information about the distribution of white and/or black pixels in said second group of pixels; and

wherein said set of parameters is arranged in one or more parameter arrays, and the elements of parameter arrays associated with consecutive input images are aligned so as to compensate movement between the consecutive images.

12. A device comprising a signal processing unit arranged to determine a set of parameters based on a binary digital image such that said set of parameters comprise information about the density of white and/or black pixels of a first group of pixels of said binary digital image, and information about the density of white and/or black pixels of a second group of pixels of said binary digital image, the information for each of the first group and the second group representing binary image data as continuous tone imagery;

wherein said set of parameters comprises information about the distribution of white and/or black pixels in said first group of pixels, and information about the distribution of white and/or black pixels in said second group of pixels; and

wherein said set of parameters is arranged in one or more parameter arrays, and the elements of parameter arrays associated with consecutive input images are aliened so as to compensate movement between the consecutive images.

13. The device of claim 12 further comprising a binary image sensor.