Image data processing method, image data processing apparatus and digital still camera

• US 6,876,385 B1
• Filed: 08/23/1999
• Issued: 04/05/2005
• Est. Priority Date: 08/24/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sano, Chikako
• Primary Examiner(s): Christensen, Andrew
• Assistant Examiner(s): GENCO, BRIAN C
• Application Number:
  US09/379,072
• Time in Patent Office: 2,052 Days
• Field of Search: 348/231.6, 348/231.99, 348/294, 348/420.1, 375/240.24, 382/254, 382/268, 382/269, 382/305, 382/266, 382/275, 382/298, 382/299
• US Class Current: 348/231.6
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

This invention relates to an image data processing method or the like capable of obtaining a preferable reproduction image based on processed image data even if the image data is short of the unit of block on reading the image data from the memory means in the unit of block. When image data of “M lines×N pixels” written in a memory is read in a unit of block consisting of the predetermined number of pixels and the read image data is subjected to a compression coding process or the like, if data of two lines and data of four pixels per line are short, data of two pixels per line is added to the left end side of the image by using data (1,1) (2,1) . . . (M,1) in the left end side thereof and data of two pixels is added to the right end side of the image by using data (1,N) (2,N) . . . (M,N) in the right end side thereof. Data of one line is added to the upper end side of the image by using data (1,1) (1,2) . . . (1,N) in the upper end side thereof and data of one line is added to the lower end side of the image by using data (M,1) (M,2) . . . (M,N) in the lower end side thereof. Thus, an image data added part is inconspicuous, and deterioration in picture quality caused by a compressing and reduction in the data compression ratio can be prevented.

Claims

1. An image data processing method comprising the steps of:

storing image data of a screen into memory means, said image data having M lines and N pixels in each of said M lines;

reading the image data from the memory means in a unit of block having K lines and L pixels in each of said K lines and processing the read image data in the unit of block; and

when the image data is read in the unit of block having said K lines and said L pixels and the read image data is short of the unit of block, said M lines are divided by said K lines resulting in a first remainder and said N pixels are divided by said L pixels resulting in a second remainder;

wherein a number of lines equal to half of said first remainder is added to an upper end of said image, data and a lower end of said image data and wherein a number of pixels equal to half of said second remainder is added to a left end of said image data and a right end of said image data.

2. An image data processing apparatus comprising:

memory means for storing image data of a screen, said image data having M lines and N pixels in each of said M lines;

memory control means for writing the image data on the memory means and reading the written image data in a unit of block;

signal processing means for performing compression coding process on the image data read from the memory means in the unit of block by the memory control means; and

format setting means for supplying a setting signal indicative of a format used when the image data stored in the memory means is recorded on a recording medium, to the memory control means and the signal processing means;

wherein the memory control means reads the image data from the memory means in a unit of block having K lines and L pixels in each of said K lines according to the format indicated by the setting signal from the format setting means and, when the image data is short of the unit of block on reading the image data, the memory control means divides said M lines by said K lines resulting in a first remainder and divides said N pixels by said L pixels resulting in a second remainder;

wherein a number of lines equal to half of said first remainder is added to an upper end of said image data and a lower end of said image data, and wherein a number of pixels equal to half of said second remainder is added to a left end of said image data and a right end of said image data.

3. An image data processing apparatus according to claim 2, wherein the signal processing means performs compression coding process according to the format indicated by the setting signal from the format setting means, on the image data read from the memory means in a unit of block.

4. A digital still camera comprising:

means for converting an image signal obtained from an image pickup device into a digital image signal;

memory means for storing image data of a screen of the digital image signal, said image data having M lines and N pixels in each of said M lines;

memory control means for controlling the memory means so as to write image data on the memory means and read the written image data in a unit of block;

signal processing means for performing compression coding process on the image data read from the memory means in the unit of block by the memory control means; and

format setting means for supplying a setting signal indicative of a format used when the image data stored in the memory means is recorded on a recording medium, to the memory control means and the signal processing means;

wherein the memory control means reads the image data from the memory means in a unit of block consisting of having K lines and L pixels in each of said K lines according to the format indicated by the setting signal from the format setting means and, when the image data is short of the unit of block on reading the image data, the memory control means divides said M lines by said K lines resulting in a first remainder and divides said N pixels by said L pixels resulting in a second remainder;

wherein a number of lines equal to half of said first remainder is added to an upper end of said image data and a lower end of said image data, and wherein a number of pixels equal to half of said second remainder is added to a left end of said image data and a right end of said image data.

5. A digital still camera comprising:

means for converting an image signal obtained from an image pickup device into a digital image signal;

memory means for storing image data of at least a screen of the digital image signals, said image data having M lines and N pixels in each of said M lines;

memory control means for controlling the memory means so as to write image data on the memory means and read the written image data in a unit of block having K lines and L pixels in each of said K lines smaller than that of the image data of a screen;

signal processing means for performing compression coding process on the image data read from the memory means in the unit of block by the memory control means; and

format setting means for supplying a setting signal indicative of a format used when the image data stored in the memory means is recorded on a recording medium, to the memory control means and the signal processing means;

wherein the memory control means reads the image data as a plurality of blocks from the memory means in the unit of block having said K lines and said L pixels according to the format indicated by the setting signal from the format setting means and, when the image data is short of the unit of block on reading the image data with respect to a predetermined block among the plurality of blocks, the memory control means divides said M lines by said K lines resulting in a first remainder and divides said N pixels by said L pixels resulting in a second remainder;

wherein a number of lines equal to half of said first remainder is added to an upper end of said image data a lower end of said image data, and wherein a number of pixels equal to half of said second remainder is added to a left end of said image data and a right end of said image data.