1. An apparatus for generating a wavelength-tunable short pulse, comprising:
(a) an ultra-short optical pulse source;
(b) an optical-property regulator for regulating the properties of an output from the ultra-short optical pulse source; and
(c) an optical fiber for receiving the output from the optical-property regulator, the optical fiber generating wavelength-tunable ultrashort pulsed light by a nonlinear optical effect through the soliton effect and Raman scattering and generating a third harmonic of the wavelength-tunable ultrashort pulsed light by a third-order nonlinear optical effect.
2. The apparatus for generating a wavelength-tunable short pulse according to claim 1, wherein the optical-property regulator is a light-intensity regulator.
3. The apparatus for generating a wavelength-tunable short pulse according to claim 1 or claim 2, wherein the wavelength of the pulsed light is altered by changing the intensity of light input to the optical fiber by the light-intensity regulator, thereby controlling the wavelength of the third harmonic.
4. The apparatus for generating a wavelength-tunable short pulse according to claim 3, wherein the wavelength of the pulsed light is altered by changing the length of the optical fiber, thereby controlling the wavelength of the third harmonic.
5. The apparatus for generating a wavelength-tunable short pulse according to claim 1 or claim 2, wherein the wavelength of the pulsed light is altered by changing the length of the optical fiber, thereby controlling the wavelength of the third harmonic.
6. A method for generating a wavelength-tunable short pulse, comprising the steps of:
(a) receiving an output from an ultra-short optical pulse source at an optical fiber, the output having passed through an optical-property regulator;
(b) generating wavelength-tunable ultrashort pulsed light by a nonlinear optical effect through the soliton effect and Raman scattering in the optical fiber; and
(c) generating a third harmonic of the wavelength-tunable ultrashort pulsed light by a third-order nonlinear optical effect in the optical fiber.
7. The method for generating a wavelength-tunable short pulse according to claim 6, wherein the optical-property regulator is a light-intensity regulator.
8. The method for generating a wavelength-tunable short pulse according to claim 6 or claim 7, wherein the wavelength of the pulsed light is altered by changing the intensity of light input to the optical fiber by the light-intensity regulator, thereby controlling the wavelength of the third harmonic.
9. The method for generating a wavelength-tunable short pulse according to claim 8, wherein the wavelength of the pulsed light is altered by changing the length of the optical fiber, thereby controlling the wavelength of the third harmonic.
10. The method for generating a wavelength-tunable short pulse according to claim 6 or claim 7, wherein the wavelength of the pulsed light is altered by changing the length of the optical fiber, thereby controlling the wavelength of the third harmonic.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for coding an image comprising the steps of:
calculating motion vectors of vertices of a patch in an image being encoded; and
outputting horizontal and vertical components of said motion vectors of said vertices and information specifying that values of the horizontal and vertical components of a motion vector for each pixel in said patch are an integral multiple of {fraction (1d)} of a distance between adjacent pixels, where d is an integer not less than 2.
2. A method for coding an image according to claim 1, wherein the value of said d is 2w, w being a positive integer.
3. A method for coding an image according to claim 1, further comprising the step of:
storing a reference image;
wherein said motion vectors of vertices of a patch in an input image is calculated by carrying out motion compensation between said input image and said reference image.
4. A method for coding an image according to claim 3, wherein the value of said d is 2w, w being a positive integer.
5. A video coder for coding an image comprising:
means for calculating motion vectors of vertices of a patch in an image being encoded; and
means for outputting horizontal and vertical components of said motion vectors of said vertices and information specifying values of the horizontal and vertical components of a motion vector for each pixel in said patch are an integral multiple of {fraction (1d)} of a distance between adjacent pixels, where d is an integer not less than 2.
6. A video coder according to claim 5, wherein the value of said d is 2w, w being a positive integer.
7. A video coder according to claim 5, further comprising:
a memory which stores a reference image;
wherein said means for calculating motion vectors is connected to said memory and reads out the reference image from said memory, and calculates said motion vectors of vertices of a patch in an input image by carrying out motion compensation between said input image and said reference image.
8. A video coder according to claim 7, wherein the value of said d is 2w, w being a positive integer.
9. A method for coding an image comprising the steps of:
storing a reference image;
calculating motion vectors of vertices of a patch in an input image by carrying out motion compensation between said input image and said reference image, in which all pixels associated with a same patch are not restricted to have a common vector and horizontal and vertical components of a motion vector for each pixel can assume an arbitrary value other than an integral multiple of a distance between adjacent pixels; and
transmitting information of said motion vectors of vertices and information specifying that values of horizontal and vertical components of a motion vector for each pixel in said patch are integral multiples of {fraction (1d1)} and {fraction (1d2)}, respectively, where each of d1 and d2 is an integer not less than 2, of a distance between adjacent pixels.