Laser print apparatus that generates pulse with value and justification value based on pixels in a multi-bit image

1. A laser print apparatus comprising:

a memory to store a multi-bit image including a plurality of pixels, each pixel represented by an N-bit value;

a modulation code generator to generate an M-bit pulse width value from the N-bit value; and

a laser print engine to form an output pixel on media based on the M-bit pulse width value, wherein the modulation code generator is operative to concatenate at least one most significant bit of a current pixel to a least significant end of the current pixel.

2. The laser print apparatus of claim 1 , wherein a window is moved across the multi-bit image to read the plurality of pixels and the plurality of pixels includes at least a center pixel, a left pixel, and a right pixel.

3. The laser print apparatus of claim 2 , further comprising:

a justification generator to generate a justification value by comparing an N-bit value of the center pixel to either an N-bit value of the left pixel or an N-bit value of the right pixel.

4. The laser print apparatus of claim 1 , wherein generating the M-bit value from the N-bit value is nonlinear.

5. A laser print apparatus comprising:

a memory to store a multi-bit image, wherein a window is moved across the multi-bit image to read a plurality of pixels at a time, the plurality of pixels including at least a center pixel, a left pixel, and a right pixel, each pixel represented by an N-bit value;

a pulse width generator to generate an M-bit pulse width value from an N-bit value of the center pixel; and

a laser print engine to form an output pixel on media based on the M-bit pulse width value.

6. The laser print apparatus of claim 5 , wherein the pulse width generator generates the M-bit pulse width value by multiplying the N-bit value by a multi-bit scaling factor.

7. The laser print apparatus of claim 5 , wherein the pulse width generator generates the M-bit pulse width value by accessing a look up table indexed by the N-bit value of the center pixel.

8. The laser print apparatus of claim 5 , wherein the pulse width generator generates the M-bit pulse width value by accessing a look up table indexed by a combination of the N-bit value of the center pixel and a portion of at least one of an N-bit value of the left pixel and an N-bit value of the right pixel.

9. The laser print apparatus of claim 5 , further comprising:

a justification generator to generate a justification value based on the N-bit value of the center pixel and either an N-bit value of the left pixel or an N-bit value of the right pixel.

10. The laser print apparatus of claim 9 , further comprising:

a comparator configured to determine whether the N-bit value of the right pixel subtracted from the N-bit value of the left pixel exceeds a predetermined number, wherein the justification value is set to a left justification when the N-bit value of the right pixel subtracted from the N-bit value of the left pixel exceeds the predetermined number.

11. The laser print apparatus of claim 9 , further comprising:

a comparator configured to determine whether the N-bit value of the left pixel subtracted from the N-bit value of the right pixel exceeds a predetermined number, wherein the justification value is set to a right justification when the N-bit value of the left pixel subtracted from the N-bit value of the right pixel exceeds the predetermined number.

12. The laser print apparatus of claim 9 , further comprising:

a comparator configured to determine whether the N-bit value of the left pixel added to the N-bit value of the right pixel exceeds a predetermined number, wherein the justification value is set to a split justification when the N-bit value of the left pixel added to the N-bit value of the right pixel exceeds the predetermined number.

13. The laser print apparatus of claim 5 , wherein generating the M-bit pulse width value from the N-bit value is nonlinear.

14. A method for calculating modulation data for modulating a laser, the method comprising:

rendering data to be printed into a multi-bit image including a plurality of pixels, each pixel represented by an N-bit value;

generating an M-bit pulse width value from the N-bit value by concatenating at least one more significant bit of a current pixel to a least significant end of the current pixel; and

printing an output pixel on a medium based on the M-bit pulse width value.

15. The method of claim 14 , further comprising:

moving a window across the multi-bit image to read the plurality of pixels, wherein the plurality of pixels includes a center pixel, a left pixel, and a right pixel.

16. The method of claim 15 , further comprising:

generating a justification value by comparing an N-bit value of the center pixel to either an N-bit value of the left pixel or an N-bit value of the right pixel.

17. The method of claim 15 , further comprising:

generating a justification value by comparing an N-bit value of the left pixel to an N-bit value of the right pixel.

18. The method of claim 17 , wherein the justification value indicates a left justification when the N-bit value of the left pixel exceeds the N-bit value of the right pixel by a predetermined amount, and the justification value indicates a right justification when the N-bit value of the right pixel exceeds the N-bit value of the left pixel by the predetermined amount.

19. The method of claim 14 , wherein generating the M-bit pulse width value from the N-bit value is nonlinear.

20. The method of claim 14 , wherein generating the M-bit pulse width value from the N-bit value is linear.