Image processing circuit of image input device
AssigneeMega Chips Corporation
InventorGen Sasaki
Life of this patent
Estimating the term…
Abstract
In image input devices such as digital still cameras, processing is speeded up and power consumption is reduced by arranging in a RPU (23) performing real time processing of a pixel data from a CCD (21), such that only special exceptional image processing not being prepared previously is subjected to a software program processing in a CPU (24) and, in post processing in which a general image processing is carried out, a pixel data temporarily stored in a main memory (29) is inputted again to the RPU (23) and then processed. This enables to sharply speed up processing, and minimize a prolonged processing in the CPU (24) to reduce power consumption, when compared to the case of executing by software problem processing.
Claims27
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units;
- and
- a central control unit in which with respect to image temporarily stored in said main memory, exceptional image processing except for said general image processing is executed as a software program processing, and then stored in said main memory, characterized in that:
- said real time processing unit has at least a selector for selecting said pixel data being photographed by said image pickup device and inputted subsequently, and said pixel data of image temporarily stored in said main memory.
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units;
- and
- a central control unit in which with respect to image temporarily stored in said main memory, exceptional image processing except for said general image processing is executed as a software program processing, and then stored in said main memory, characterized in that:
- said real time processing unit has a cumulative addition processing function of, when each pixel data photographed by said image pickup device and inputted sequentially extends multiple frames, repeating, a predetermined number of times, a cumulative addition processing in which a pixel data residing on the same position in the preceding frame temporarily stored in said main memory is added to each pixel data in each of said frames from said image pickup device and the result is stored in said memory.
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units;
- and
- a central control unit in which with respect to image temporarily stored in said main memory, exceptional image processing except for said general image processing is executed as a software program processing, and then stored in said main memory, characterized in that:
- said real time processing unit has a circulating addition processing function of, when each pixel data photographed by said image pickup device and inputted sequentially extends multiple frames, repeating, a predetermined number of times, a circulating addition processing in which a pixel data residing on the same position in the preceding frame temporarily stored in said main memory and each pixel data in each of said frames from said image pickup device are respectively subjected to multiplication with a predetermined weighting factor, followed by addition, and the results are stored in said memory;
- and said weighting factor used in said circulating addition processing comprising a first factor to be multiplied to a pixel data residing at the same position in the preceding frame temporarily stored in said main memory, and a second factor to be multiplied to each pixel data in each frame from said image pickup device, said first and second factors being set such that the sum of these factors is always one.
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units;
- and
- a central control unit in which with respect to image temporarily stored in said main memory, exceptional image processing except for said general image processing is executed as a software program processing, and then stored in said main memory, characterized in that:
- said real time processing unit has a pixel compensation function with which each pixel data photographed by said image pickup device and inputted sequentially is multiplied by a predetermined pixel compensation parameter previously stored in said main memory, for a predetermined pixel compensation including shading compensation.
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- and
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units, and wherein,
- said real time processing unit further comprises a defective pixel compensation block that reads defective pixel addresses stored in said main memory disposed outside of said real time processing unit, and performs defective pixel compensation when a pixel address of a pixel data residing in image matches said defective pixel address.
An image processing circuit of an image input device which performs a predetermined image processing of image photographed by an image pickup device in said image input device, said circuit comprising:
- a real time processing unit in which a predetermined general image processing of a pixel data being photographed by said image pickup device and inputted sequentially is performed by real time processing;
- a main memory that stores a pixel data outputted from at least said real time processing unit, in image frame units;
- and
- a central control unit in which with respect to image temporarily stored in said main memory, exceptional image processing except for said general image processing is executed as a software program processing, and then stored in said main memory, characterized in that:
- said real time processing unit further comprises:
- a gamma compensation table capable of performing, when given a N-bit length pixel data, gamma compensation processing about said pixel data;
- and
- a selector in which, when given a N-bit length pixel data, said pixel data is inputted to said gamma compensation table;
- and when given a (N−2)-bit length pixel data, switching is made so that four data rows sequentially provided as a (N−2)-bit length pixel data, are respectively inputted to four look-up tables obtained by dividing said gamma compensation table into four.
Dependencies are inferred from the claim text.