1. A system comprising:
a population of items each including a tag, each tag including a plurality of identification bits and a plurality of redundancy bits; and
a tag reader configured to read tags and determine the identification bits of at least one unreadable tag in the population based on the identification bits and the redundancy bits of at least one readable tag in the population.
2. The system of claim 1, wherein the tag reader is configured to determine whether an item belongs to the population and to determine which tags in the population were unreadable.
3. The system of claim 1, wherein each tag comprises one of a radio-frequency identification (RFID) chip and a bar code label.
4. The system of claim 1, further comprising:
a tag writer configured to write the plurality of identification bits and the plurality of redundancy bits to each tag in the population,
wherein the tag writer is configured to write to each redundancy bit of each tag in the population an XOR chain of identification bits from other tags in the population, and
wherein the tag reader is configured to determine the identification bits of the at least one unreadable tag from the XOR chain in each redundancy bit of at least one readable tag in the population.
5. The system of claim 4, wherein a definition of each XOR chain of identification bits is stored in a database or embedded within the tag writer and the tag reader.
6. The system of claim 4, wherein a length of each XOR chain is set to provide a selected probability of 100 percent recovery of identification bits of unreadable tags in the population for a given percentage of unreadable tags.
7. A system comprising:
means for reading a population of tags, each tag associated to an item, each tag including a plurality of identification bits and a plurality of population redundancy bits; and
means for recovering identification bits of an unreadable tag in the population based on the identification bits and the population redundancy bits of at least one readable tag in the population.
8. The system of claim 7, further comprising:
means for writing the population of tags, including writing an XOR chain of identification bits of other tags in the population to each population redundancy bit of each tag in the population.
9. The system of claim 8, further comprising:
means for determining an optimal length of each XOR chain to provide a selected probability of 100 percent recovery of identification bits of unreadable tags in the population for a given percentage of unreadable tags.
10. A method for recovering data from an unreadable tag in a population of items each including a tag, the method comprising:
reading a population of tags, each tag including a plurality of identification bits and a plurality of population redundancy bits;
determining which tags within the population were unreadable; and
determining the identification bits of unreadable tags within the population based on the identification bits and the population redundancy bits of at least one readable tag in the population.
11. The method of claim 10, further comprising:
writing the population of tags, including writing an XOR chain of identification bits of other tags in the population to each population redundancy bit of each tag in the population.
12. The method of claim 11, further comprising:
storing definitions of each XOR chain in a database.
13. The method of claim 11, further comprising:
determining a length of each XOR chain by running simulations to determine the optimal length of each XOR chain to maximize recovery of the identification bits of unreadable tags in the population.
14. The method of claim 13, further comprising:
determining a number of simulations to run based on a number of items in the population and a number of population redundancy bits for each tag.
15. The method of claim 13, wherein determining the length of each XOR chain comprises determining the length of each XOR chain to maximize recovery of the identification bits for a defined percentage of unreadable tags in the population.
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. An image processing apparatus comprising:
an image input device which receives a stereoscopic photographed image composed of a plurality of photographed images respectively captured with a plurality of image pickup devices;
a face detecting device which detects faces from each of the photographed images;
a face position identifying device which identifies positions of the detected faces in each of the photographed images;
an in-focus position identifying device which identifies in-focus positions in each of the photographed images;
a distance information acquiring device which acquires distance information on the positions of the faces based on the positions of the faces, a relative distance between the plurality of image pickup devices, and photographing directions of each of the image pickup devices;
a focusing state identifying device which identifies focusing states in the positions of the faces based on the in-focus positions and the distance information on the positions of the faces;
a face frame generating device which generates face frames, each face frame being an overlay which is generated over a corresponding face of said faces, the overlay being different from said corresponding face, the face frames indicating the positions of the faces, the face frames being blurred according to the focusing states of the positions of the faces; and
a stereoscopic display image generating device which generates a stereoscopic display image from the generated face frames and the stereoscopic photographed image.
2. The image processing apparatus according to claim 1,
wherein the distance information acquiring device acquires distance information on the positions of the faces based on the positions of the faces, and on the lengths of baseline and angles of convergence of the plurality of image pickup devices.
3. The image processing apparatus according to claim 1,
wherein the focusing state identifying device identifies whether each of the positions of the faces is in focus state or out of focus state, and
when it is identified that a position of a face is out of focus state, the face frame generating device changes a face frame of the face to a blurred state, compared to when the position of the face is in focus state.
4. The image processing apparatus according to claim 1,
wherein the focusing state identifying device identifies defocus amounts in respective positions of the faces as the focusing states, and
the face frame generating device changes blurring amounts of respective face frames according to the defocus amounts.
5. The image processing apparatus according to claim 1,
wherein the distance information acquiring device detects as parallax amounts of the faces, differences of the positions of the faces between the plurality of photographed images and determines distance information on the positions of the faces at least based on the parallax amounts.
6. The image processing apparatus according to claim 1,
wherein the face frame generating device generates stereoscopic face frames indicating the positions of the faces in a manner allowing stereoscopic vision, the stereoscopic face frames blurred according to the focusing states in the positions of the faces.
7. The image processing apparatus according to claim 1, further comprising an image display device which displays the display image.
8. A camera comprising an image processing apparatus according to claim 1.
9. An image processing method comprising:
an image input step of receiving a stereoscopic photographed image composed of a plurality of photographed images respectively captured with a plurality of image pickup devices;
a face detecting step of detecting faces from each of the photographed images;
a face position identifying step of identifying positions of the detected faces in each of the photographed images;
an in-focus position identifying step of identifying in-focus positions in each of the photographed images;
a distance information acquiring step of acquiring distance information on the positions of the faces based on the positions of the faces, a relative distance between the plurality of image pickup devices, and photographing directions of each of the image pickup devices;
a focusing state identifying step of identifying focusing states in the positions of the faces based on the in-focus positions and the distance information on the positions of the faces;
a face frame generating step of generating face frames, each face frame being an overlay which is generated over a corresponding face of said faces, the overlay being different from said corresponding face, the face frames indicating the positions of the faces, the face frames being blurred according to the focusing states of the positions of the faces; and
a stereoscopic display image generating step of generating a stereoscopic display image from the generated face frames and the stereoscopic photographed image.
10. The image processing apparatus according to claim 1, wherein
said face frame generating device performs a filtering processing of blurring a face frame corresponding to one of said faces, by applying a Gaussian filter so that a pixel in the inner side of said face frame is blurred,
wherein
said face frame generating device does not apply said filtering processing to a face frame when the face position is in an in-focus state, and
said face frame generating device applies said filtering processing to a face frame when the face position is in an out-of-focus state.
11. The image processing apparatus according to claim 1, wherein
a blurred face frame is stored in a storage unit, and
when a defocus amount of a face position is not in an allowable range, a face frame corresponding to said face is switched to said blurred face frame.