Method and apparatus for recording/reproducing mesh pattern data

• US 5,153,928 A
• Filed: 05/30/1990
• Issued: 10/06/1992
• Est. Priority Date: 06/09/1989
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures Holding 56 LLC (Intellectual Ventures LLC)
• Original Assignee: Casio Computer Company Limited
• Inventors: Iizuka, Nobuo
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): COUSO, YON JUNG
• Application Number:
  US07/530,630
• Time in Patent Office: 860 Days
• Field of Search: 382/65, 382/9, 382/10, 382/27, 382/56, 382/57, 382/61, 382/48, 358/409, 358/410
• US Class Current: 382/321
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 19/06075 the marking containing means for error correction
• CPC Class Codes: G06K 2019/06262 with target- or other orientation-indicating feature
• CPC Class Codes: G06K 7/016 Synchronisation of sensing process
• CPC Class Codes: G06K 7/1093 sensing, after transfer of the image of the data-field to an intermediate store, e.g. storage with cathode ray tube
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06K 7/1473 error correction
• CPC Class Codes: G06T 9/001 Model-based coding, e.g. wire frame

Abstract

Recorded data is read by an image sensor from a recording medium on which the data is two-dimensionally recorded in a mesh pattern, and the read data is stored in an image RAM. The stored data is subjected to data decoding and error correction to reproduce target data. A scanning reference pattern of a mesh pattern recorded on the recording medium serves as a guide when the stored recorded data read by the image sensor is reproduced by scanning in the image RAM. A reproduction apparatus has a capability of coping with a partial destruction of the scanning reference pattern. Error checking codes are added to the recording medium in addition to the target data. These items of data are recorded as an encoded image after being subjected to scrambling processing and randomization processing. The reproduction apparatus can easily cope with an error when the encoded image is reproduced.

Claims

1. A data reading method of reading data encoded as an image recorded on a recording medium, comprising the steps of:

(A) reading image data representing an image from the recording medium on which the image is recorded, said image being constituted by (i) a mesh pattern including a plurality of black and white meshes arrayed in a matrix, said mesh pattern being obtained by encoding data, and (ii) a main scanning reference pattern for indicating a data sampling reference in a main scanning direction of the mesh pattern;

(B) dividing the read image data into a plurality of partial image data segments;

(C) searching feature pixel groups featuring pieces of the main scanning reference pattern from the partial image data segments, said feature pixel groups lying within the partial image data segments;

(D) determining positions of pieces of the main scanning reference pattern in the partial image data segments from which the feature pixel groups are not detected in said searching step by executing an interpolation process on the basis of positions of pieces of the main scanning reference pattern which have been detected in the searching step for other partial image data segments, thereby generating position data of the pieces of the main scanning reference pattern on the image data; and

(E) identifying black and white levels of meshes of the mesh pattern by detecting levels of the image data at positions designated on the basis of the generated position data.

2. A data reading apparatus for reading data encoded as an image recorded on a recording medium, comprising:

(A) image sensor means for reading image data representing an image from the recording medium on which an image is recorded, said image being constituted by (i) a mesh pattern including a plurality of black and white meshes arrayed in a matrix, said mesh pattern being obtained by encoding data, and (ii) a main scanning reference pattern for indicating a data sampling reference in a main scanning direction of the mesh pattern;

(B) segmentation means for dividing read image data into a plurality of partial image data segments;

(C) main scanning reference pattern searching means for searching feature pixel groups featuring pieces of the main scanning reference pattern from the partial image data segments, said feature pixel groups lying within the partial image data segments;

(D) main scanning reference pattern position generating means for determining positions of pieces of the main scanning reference pattern in the partial image data segments from which the feature pixel groups are not detected by said main scanning reference pattern searching means by executing an interpolation process on the basis of positions of pieces of the main scanning reference pattern which have been detected from other partial image data segments by said main scanning reference pattern searching means, thereby generating position data of the pieces of the main scanning reference pattern on the image data; and

(E) identification means for identifying black and white levels of meshes of the mesh pattern by detecting levels of the image data at positions designated on the basis of the generated positions data.

3. An apparatus according to claim 2, wherein:

said main scanning reference pattern of said recording medium comprises two guide lines extending on two sides of said mesh pattern; and

said main scanning reference pattern searching means includes means for searching three white, black, and white run lengths having predetermined intervals and extending along a depth direction perpendicular to said main scanning direction of said image data as said feature pixel groups featuring pieces of image data of said guide lines.

4. A data reading method of reading data encoded as an image recorded on a recording medium, comprising the steps of:

(A) reading image data representing an image from the recording medium on which the image is recorded, said image being constituted by (i) a mesh pattern including a plurality of black and white meshes arrayed in a matrix, said mesh pattern being obtained by encoding data, and (ii) a scanning reference pattern having synchronous marks which are arranged in meshes having an interval synchronous with that of the meshes of said mesh pattern;

(B) searching the synchronous marks of said scanning reference pattern from the read image data, the searching step including the substeps of;

(a) detecting at least one synchronous mark to determine a feature parameter including a position thereof,

(b) predicting a position of an adjacent synchronous mark on the basis of the determined feature parameter,

(c) actually measuring the adjacent synchronous mark using the predicted position as the center,

(d) comparing the actually measured position with the predicted position,

(e) determining the position of the adjacent synchronous mark according to the actual measurement result when a coincidence is found between the positions, and determining the position of the adjacent synchronous mark on the basis of the determined feature parameter when a noncoincidence is found between the actually measured and the predicted positions, and

(f) repeating the substeps (b), (c) (d) and (e) for all of the synchronous marks to generate position data of all of the synchronous marks; and

(C) identifying black and white levels of the meshes of said mesh pattern by detecting levels of the image data at positions designated on the basis of the generated position data.

5. A data reading apparatus for reading data encoded as an image recorded on a recording medium, comprising:

(A) image sensor means for reading image data representing an image from the recording medium on which an image is recorded, said image being constituted by (i) a mesh pattern including a plurality of black and white meshes arrayed in a matrix, said mesh pattern being obtained by encoding data, and (ii) a scanning reference pattern having synchronous marks which are arranged in meshes having an interval synchronous with that of the meshes of said mesh pattern;

(B) searching means for searching the synchronous marks of said scanning reference pattern from the read image data, said searching means comprising;

(a) means for detecting at least one synchronous mark to determine a feature parameter including a position thereof,

(b) means for predicting a position of an adjacent synchronous mark on the basis of the determined feature parameter,

(c) means for actually measuring the adjacent synchronous mark using the predicted position as a center,

(d) means for comparing the actually measured position with the predicted position,

(e) means for, when a coincidence is found between the positions, determining the position of the adjacent synchronous mark according to the actual measurement result, and for, when a noncoincidence is found between the actually measured and the predicted positions, determining the position of the adjacent synchronous mark on the basis of the determined feature parameter, and

(f) means for repeating operations of said means (b), (c), (d) and (e) for all of the synchronous marks to generate position data of all of the synchronous marks; and

(C) identification means for identifying black and white levels of the meshes of said mesh pattern by detecting levels of the image data at positions designated on the basis of the generated position data.

6. An apparatus according to claim 5, wherein:

at least one of a main scanning reference pattern and a sub-scanning reference pattern is formed on said recording medium; and

said searching means includes means for searching a synchronous mark of at least one of said main scanning reference pattern and said sub-scanning reference pattern from the read image data.