Abstract: An image processing device changes degree of noise reduction for image data in accordance with tone correction to be performed according to the image data and includes a change rate acquisition part and a noise reduction part. The change rate acquisition part obtains, at a plurality of portions in the image data, a change rate of a signal level of the image data before and after tone correction. The noise reduction part controls a degree of noise reduction for each portion in the image data according to the change rate.

Abstract: An image compression device includes a transformation part for subjecting image data to frequency decomposition and for determining transformation coefficients, a coefficient adjustment part for altering the transformation coefficients according to imaging conditions for obtaining the image data, and an encoding part for encoding the altered transformation coefficients.

Abstract: An image processing apparatus reduces a distortion that occurs at a tile boundary (tile distortion) when an image is compressed or expanded on a tile-by-tile basis. It is equipped with a tone jump detecting section, a slope calculating section, and a slope correcting section. The tone jump detecting section calculates differences between the values of pixels on both sides of the tile boundary and detects a tone jump in the tile distortion according to the differences. The slope calculating section calculates slope-like correction values to be used for causing the tone jump to approach zero in a prescribed length ((prescribed length)<(tile length)), and adds the slope-like correction values to the values of pixels near the tile boundary. As a result, the steep tone jump due to the tile distortion is corrected into a gentle slope-like variation. Tile distortions are reduced properly by this processing.

Abstract: As the target compression rate is set higher, the ratio of a DC component quantization step and an AC component quantization step (referred to as a “DC/AC quantization ratio” is adjusted to a smaller value and then a compression size adjustment is implemented while sustaining the DC/AC quantization ratio at a substantially constant value. In addition, if the compression rate is set higher than a predetermined factor, the DC/AC quantization ratio is fixed at a constant value regardless of the target compression rate setting to prevent the DC component quantization step from becoming excessively small.

Abstract: A portion of the capacity of a storage medium is set aside in advance as an adjustment capacity to be utilized in making an adjustment on the extent by which the target code volume is exceeded during a fixed-length compression. A nominal remaining frame quantity calculated by excluding the adjustment capacity from the remaining capacity is indicated as the remaining frame quantity at the storage medium to prevent any irregular change in the number of remaining frames displayed at the electronic camera. In addition, by allowing the compression code volume to exceed the target in correspondence to the excess (the estimated capacity value representing the remaining area) of the remaining capacity, a planned reduction in the remaining area is achieved.

Abstract: The object of the present invention is to provide an image encoding device for designating a selected region constituting a region to which a greater quantity of information is allocated in an image. Thus, the present invention provides an image encoding device including a transformation component for converting an image into transformation coefficients by subjecting the image to a frequency decomposition. The image encoding device further includes a dividing component for dividing the transformation coefficients produced by the transformation component into a “selected region on the image” and a “non-selected region other than the selected region,” and an encoding component for encoding the transformation coefficients by allocating a greater quantity of information to the selected region than to the non-selected region. The image encoding device yet further includes a region adjustment component for controlling a bit allocation rate of the non-selected region by adjusting the area of the selected region.

Abstract: A data compression method includes: a quantization trial step in which input data are quantized using an initial quantization table set in advance; a coding trial step in which a code volume achieved when data that have undergone quantization in the quantization trial step are coded is determined; a relationship ascertaining step in which a scale factor in the initial quantization table and the code volume are substituted in “a relational expression representing a relationship between a code volume and a scale factor” containing two undetermined parameters “a” and “b” and the undetermined parameters in the relational expression are ascertained based upon “the relational expression after substitution” and “a statistical relationship between the undetermined parameters “a” and “b” determined through a previous quantization operation;” a scale factor determining step in which a target scale factor corresponding to a target code v

Abstract: A data compression method includes: a quantization trial step in which input data are quantized using an initial quantization table set in advance; a coding trial step in which a code volume achieved when data that have undergone quantization in the quantization trial step are coded is determined; a relationship ascertaining step in which a scale factor in the initial quantization table and the code volume are substituted in “a relational expression representing a relationship between a code volume and a scale factor” containing two undetermined parameters “a” and “b” and the undetermined parameters in the relational expression are ascertained based upon “the relational expression after substitution” and “a statistical relationship between the undetermined parameters “a” and “b” determined through a previous quantization operation;” a scale factor determining step in which a target scale factor corresponding to a target code v

Abstract: An image compression device includes a transformation part for subjecting image data to frequency decomposition and for determining transformation coefficients, a coefficient adjustment part for altering the transformation coefficients according to imaging conditions for obtaining the image data, and an encoding part for encoding the altered transformation coefficients.

Abstract: The object of the present invention is to provide an image encoding device for designating a selected region constituting a region to which a greater quantity of information is allocated in an image. Thus, the present invention provides an image encoding device including a transformation component for converting an image into transformation coefficients by subjecting the image to a frequency decomposition. The image encoding device further includes a dividing component for dividing the transformation coefficients produced by the transformation component into a “selected region on the image” and a “non-selected region other than the selected region,” and an encoding component for encoding the transformation coefficients by allocating a greater quantity of information to the selected region than to the non-selected region.