Image compression apparatus and method, image regeneration apparatus, camera and camera system

Abstract

A process and apparatus for displaying and recording image data can be smoothly performed in characteristic methods by computing a quantization parameter for use in compression of image data, obtaining a difference in the amount of processes between the display of image data and the recording of image data, and managing memory of temporarily stored image data for regeneration of recorded image data.

1 . An image compression apparatus which compresses input images according to a quantization parameter, comprising:
 a computation unit computing the quantization parameter by performing trial compression on an input image;   a control unit operating the computation unit for images input at a time interval longer than a predetermined time corresponding to each input image, and operating the computation unit for images input at a time interval shorter than a predetermined time corresponding to each image input at an interval of a predetermined number of images; and   a processing unit compressing input images according to the computed quantization parameter.   
   
   
       2 . The image compression apparatus according to  claim 1 , characterized in that
 the image compression apparatus is incorporated into a digital camera.   
   
   
       3 . The image compression apparatus according to  claim 1 , characterized in that
 the processing unit performs a compression process according to a latest computed quantization parameter on an input image input at the shorter time interval for which no quantization parameter has been computed.   
   
   
       4 . The image compression apparatus according to  claim 3 , characterized in that
 the image compression apparatus is incorporated into a digital camera.   
   
   
       5 . The image compression apparatus according to  claim 1 , characterized in that
 the control unit operates the computation unit for images input at a time interval shorter than a predetermined time corresponding to each image input at an interval of a predetermined number of images when the input images are continuously shot or captured as moving pictures.   
   
   
       6 . The image compression apparatus according to  claim 5 , characterized in that
 the image compression apparatus is incorporated into a digital camera.   
   
   
       7 . An image compressing method for compressing an input image according to a quantization parameter, comprising the steps of:
 performing trial compression on each input image for an image input at a time interval longer than a predetermined time, thereby computing each quantization parameter corresponding to each input image; and   performing trial compression on images input at an interval of a predetermined number of images whenever the image is input, for an image input at a time interval shorter than said predetermined time, thereby computing the quantization parameter, and   compressing the input images according to each computed quantization parameter corresponding to each input image.   
   
   
       8 . A computer-readable storage medium storing a program used to direct a computer to perform the procedures of:
 computing each quantization parameter by performing trial compression on each input image for images input at a time interval longer than a predetermined time, and performing a compression process according to each computed quantization parameter corresponding to each input image; and   computing each quantization parameter by performing trial compression on each input image at an interval of a predetermined number of images, whenever the images are input, for the images input at a time interval shorter than said predetermined time, and performing a compression process according to each computed quantization parameter corresponding to each input image.   
   
   
       9 . A camera, comprising:
 a capture unit obtaining an electronic image of a subject by capturing the subject through a shooting optic system;   an image processing unit generating digital image data by processing a signal output from the capture unit;   a reduction unit performing a compression process or a thinning process on the image data output from the image processing unit; and   a communications unit transmitting the image data to an external device, characterized in that   the reduction unit determines a compression rate of the image data before inputting a capture designation signal higher than that after the input of the capture designation signal, or determines an amount of thinning of the image data before the input of the capture designation signal larger than that after the input of the capture designation signal.   
   
   
       10 . A camera system which transmits image data captured by a camera to an external device, and stores and displays the data on the external device, characterized in that
 the camera transmits data after processing the data such that an amount of image data for display can be smaller than an amount of image data for storage.   
   
   
       11 . The camera system according to  claim 10 , comprising:
 an external device comprising a display unit for displaying image data captured by the camera, a storage unit for storing the image data captured by the camera, and a communications unit capable of communicating with the camera, characterized in that   the storage unit stores only image data received from the communications unit having a lower compression rate or having a smaller amount of thinned data compared to image data to be displayed.   
   
   
       12 . The camera system according to  claim 10 , characterized in that
 the external device performs one of a displaying operation and a storing operation on the image data by identifying the image data transmitted from the camera.   
   
   
       13 . The camera system according to  claim 10 , characterized in that
 the external device performs one of a displaying operation and a storing operation on the image data corresponding to an amount of image data transmitted from the camera.   
   
   
       14 . A camera which transmits image data for display by wireless means to an external device before inputting a capture designation signal, and transmits image data for storage by wireless means to an external device after inputting a capture designation signal, characterized in that
 amounts of transmission data are different before and after inputting a capture designation signal.   
   
   
       15 . An image regeneration apparatus, which regenerates image data of at least one image data group of image data including representative image data and plural pieces of image data associated with the representative image data or a single piece of image data, provided by a record medium built in the apparatus or a record medium mounted on the apparatus, comprising:
 a temporary storage unit temporarily storing at least one piece of representative image data in the representative image data and the image data group, or the single piece of image data;   an image selection unit selecting from said temporary storage unit a piece of image data as an image to be displayed from representative image data or a single piece of image data;   a reproduction designation unit designating for regeneration of an image data group associated with selected representative image data when the representative image data is selected by the image selection unit; and   a storage control unit controlling the image data of the image data group to be temporarily stored in the temporary storage unit before regeneration of the image data group by the regeneration designation.   
   
   
       16 . The image regeneration apparatus according to  claim 15 , characterized in that
 the image data group comprises a group of image data configuring moving pictures.   
   
   
       17 . The image regeneration apparatus according to  claim 15 , characterized in that
 each piece of image data of the representative image data and the single piece of image data is formed by frame information about a date and time or a shooting order; and   the image selection unit selects image data of either the temporarily stored representative image data or a piece of image data responsive to the frame information.   
   
   
       18 . The image regeneration apparatus according to  claim 15 , characterized in that
 the temporary storage unit comprises:
 a first storage area for temporarily storing image data selected by the image selection unit and a single piece of image data or representative image data in an image selecting order before and after the image data; and 
 a second storage area for temporarily storing a single piece of image data or representative image data excluding the image data temporarily stored in the first storage area, or an image data group associated with the representative image data temporarily stored in the first storage area. 
   
   
   
       19 . The image regeneration apparatus according to  claim 18 , characterized in that:
 each piece of image data of the representative image data and the single piece of image data includes frame information relating to a date and time or shooting order; and   the storage control unit controls storing of representative image data selected by the image selection unit and a single piece of image data or representative image data having the frame information adjacent to the representative image data in the first storage area, and controls storing of the image data group associated with the selected representative image data in the second storage area, prior to the regeneration of the image data group by the regeneration designation.   
   
   
       20 . An image regeneration apparatus which displays at least representative image data or any of a single piece of image data, in an image data group including the representative image data and plural pieces of image data related to the representative image data, or in a single piece of image data, comprising:
 a temporary storage unit temporarily storing at least the representative image data or any of a single piece of image data in the representative image data, the image data group, or the single piece of image data;   an image selection unit selecting a piece of image data as an image to be displayed from the temporarily stored representative image data or a piece of image data; and   a storage control unit for controlling storage using an image data group related to the selected image data or related image data by making a predetermined determination with the selected image data for a specified storage area by specifying a storage area having a predetermined priority from a storage area of the temporary storage unit depending on whether the selected image data is representative image data or a piece of image data.   
   
   
       21 . The image regeneration apparatus according to  claim 20 , characterized in that:
 each piece of image data of the representative image data and the single piece of image data includes frame information relating to the date and time or a shooting order; and   the storage control unit controls storage of a representative image data or a piece of image data adjacent relative to the frame information of the selected image data, in a storage area having a high selection priority in selecting order.   
   
   
       22 . The image regeneration apparatus according to  claim 20 , characterized in that
 when the selected image data is representative image data, the storage control unit controls storage such that the image data group associated with the representative image data can be stored in the regenerating order of the image data group in a storage area having a lower selection priority order.   
   
   
       23 . The image regeneration apparatus according to  claim 20 , characterized in that:
 each piece of image data of the representative image data and the single piece of image data comprises frame information about a date and time or a shooting order; and   when the selected image data is a piece of image data, the storage control unit controls storage such that a piece of image data or representative image data in a selecting order according to the frame information can be sequentially stored in a storage area having a higher selection priority order.