Abstract: In a preparation operation of a distortion correcting method, actual measured lens position information obtained by an optical system at a time of shooting an image, an error range in the lens position information, and a relational expression between a distortion pattern and the lens position information, are respectively obtained. In a correcting operation, actual measured data of the lens position information is fit to the relational expression to estimate the distortion pattern of the image shot by the optical system, and a temporary corrected image is obtained. In a selection operation, a distortion correcting pattern to be applied in main correcting performed on the image is selected based on the temporary corrected image. In a repeating operation, when the distortion correcting pattern is not selected, a value of the actual measured data is adjusted within the error range and the correcting operation is repeated.

Abstract: The present invention is intended to record image data having a wide dynamic range is a file together with image data having a narrow dynamic range. First, an image recording apparatus separately gradation-converts image data to be recorded into primary data having a narrow dynamic range and secondary data having a wide dynamic range. Then, the image recording apparatus calculates data that determines correlation between the primary data and secondary data and employs the calculated data as tertiary data. The image recording apparatus records the primary data and the tertiary data in a file. On the other hand, an image reproducing apparatus reads out primary data and tertiary data that were recorded in the above manner and reproduces secondary data having a wide dynamic range based on the primary data and the tertiary data.

Abstract: In a preparation operation of a distortion correcting method, actual measured lens position information obtained by an optical system at a time of shooting an image, an error range in the lens position information, and a relational expression between a distortion pattern and the lens position information, are respectively obtained. In a correcting operation, actual measured data of the lens position information is fit to the relational expression to estimate the distortion pattern of the image shot by the optical system, and a temporary corrected image is obtained. In a selection operation, a distortion correcting pattern to be applied in main correcting performed on the image is selected based on the temporary corrected image. In a repeating operation, when the distortion correcting pattern is not selected, a value of the actual measured data is adjusted within the error range and the correcting operation is repeated.

Abstract: An image compressor of the present invention includes a difference calculating unit and a difference requantizing unit. The difference calculating unit calculates a predicted difference between a pixel value of image data and a predicted value (a calculated value of the pixel value predicted from known data). When a magnitude of the predicted difference exceeds a predefined threshold value, the difference requantizing unit applies the coarse quantization steps to requantize the predicted difference to keep a bit range to predetermined size. In this manner, compressed data, in which a bit length of the predicted difference for one pixel is adjusted to a fixed bit length, is generated.

Abstract: An electronic camera that creates an image file by processing image data obtained through an image-capturing operation, includes: an image-capturing unit that generates the image data by capturing a subject image; a data extraction unit that sets an image plane range corresponding to an image portion of the image data and extracts data of the image portion in the image plane range; a data insertion unit that writes data of a predetermined specific image over the image plane range of the image data and generates data of a processed image; and a file creation unit that creates an image file by storing the data of the processed image into an image data area of the image file, which is referenced as image data and storing the data of the image portion into a non-image data area of the image file which is not referenced as image data.

Abstract: The present invention is intended to record image data having a wide dynamic range is a file together with image data having a narrow dynamic range. First, an image recording apparatus separately gradation-converts image data to be recorded into primary data having a narrow dynamic range and secondary data having a wide dynamic range. Then, the image recording apparatus calculates data that determines correlation between the primary data and secondary data and employs the calculated data as tertiary data. The image recording apparatus records the primary data and the tertiary data in a file. On the other hand, an image reproducing apparatus reads out primary data and tertiary data that were recorded in the above manner and reproduces secondary data having a wide dynamic range based on the primary data and the tertiary data.

Abstract: The present invention is intended to record image data having a wide dynamic range is a file together with image data having a narrow dynamic range. First, an image recording apparatus separately gradation-converts image data to be recorded into primary data having a narrow dynamic range and secondary data having a wide dynamic range. Then, the image recording apparatus calculates data that determines correlation between the primary data and secondary data and employs the calculated data as tertiary data. The image recording apparatus records the primary data and the tertiary data in a file. On the other hand, an image reproducing apparatus reads out primary data and tertiary data that were recorded in the above manner and reproduces secondary data having a wide dynamic range based on the primary data and the tertiary data.

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: An image data coding apparatus having a coding unit that generates coded data after generating a transform coefficient by implementing Wavelet transform on image data, includes: a storage unit that stores coded data which the coding unit generates by coding image data which have not been sub-sampled; an information obtaining unit that obtains compression-related information indicating a compression rate or a restored image quality; and a re-coding unit that changes a sub-sampling ratio of individual color components constituting the coded data stored in the storage unit in conformance to the compression-related information and generates new coded data.

Abstract: An image compressor of the present invention includes a difference calculating unit and a difference requantizing unit. The difference calculating unit calculates a predicted difference between a pixel value of image data and a predicted value (a calculated value of the pixel value predicted from known data). When a magnitude of the predicted difference exceeds a predefined threshold value, the difference requantizing unit applies the coarse quantization steps to requantize the predicted difference to keep a bit range to predetermined size. In this manner, compressed data, in which a bit length of the predicted difference for one pixel is adjusted to a fixed bit length, is generated.

Abstract: The present invention performs gradation conversion linearly on an image signal when the image signal is darker than a preset value. Consequently, the dark region of the image is not distorted nonlinearly, and the gradations of shadows and hair can be reproduced in full richness. On the other hand, gradation conversion is performed nonlinearly on image signals if the image signal is brighter than a preset value. The nonlinear conversion in this case: (1) has a slope that effectively equalizes an average noise amplitude of the image signal without being based on the output gradation value, and (2) is offset so as to be continuous with the gradation conversion characteristic of the dark area gradation conversion unit. Through condition (1), the level-dependent noise in the bright region is equalized. Furthermore, through condition (2), gradation differences and gradation reversals do not occur at the boundary between the dark region and the bright region.

Abstract: An image encoding device equipped with a transformation component which transforms given image data into transformation coefficients by subjecting this image data to a frequency decomposition, a dividing component which divides 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 which encodes the transformation coefficients by preferentially allocating a greater quantity of information to the selected region than to the non-selected region, and the dividing component performs an equation evaluation of numerical equation data that stipulates the boundary of the selected region, and determines whether the transformation coefficients belong to the selected region on the basis of the results of this equation evaluation, to perform the division into a selected region and non-selected region during image encoding with less processing.

Abstract: The present invention performs gradation conversion linearly on an image signal when the image signal is darker than a preset value. Consequently, the dark region of the image is not distorted nonlinearly, and the gradations of shadows and hair can be reproduced in full richness. On the other hand, gradation conversion is performed nonlinearly on image signals if the image signal is brighter than a preset value. The nonlinear conversion in this case: (1) has a slope that effectively equalizes an average noise amplitude of the image signal without being based on the output gradation value, and (2) is offset so as to be continuous with the gradation conversion characteristic of the dark area gradation conversion unit. Through condition (1), the level-dependent noise in the bright region is equalized. Furthermore, through condition (2), gradation differences and gradation reversals do not occur at the boundary between the dark region and the bright region.

Abstract: An electronic camera that creates an image file by processing image data obtained through an image-capturing operation, includes: an image-capturing unit that generates the image data by capturing a subject image; a data extraction unit that sets an image plane range corresponding to an image portion of the image data and extracts data of the image portion in the image plane range; a data insertion unit that writes data of a predetermined specific image over the image plane range of the image data and generates data of a processed image; and a file creation unit that creates an image file by storing the data of the processed image into an image data area of the image file, which is referenced as image data and storing the data of the image portion into a non-image data area of the image file which is not referenced as image data.

Abstract: An image data compression method invention for compressing image data including pixel data having a specific number of bits per pixel obtained at an image input device, includes: a step in which the pixel data having the specific number of bits are divided into higher-order bit data having a first number of bits and lower-order bit data having a second number of bits; and a step in which at least the higher-order bit data resulting from division are compressed through a specific compression method.

Abstract: An image data coding apparatus having a coding unit that generates coded data after generating a transform coefficient by implementing Wavelet transform on image data, includes: a storage unit that stores coded data which the coding unit generates by coding image data which have not been sub-sampled; an information obtaining unit that obtains compression-related information indicating a compression rate or a restored image quality; and a re-coding unit that changes a sub-sampling ratio of individual color components constituting the coded data stored in the storage unit in conformance to the compression-related information and generates new coded data.

Abstract: An image encoding device equipped with a transformation component which transforms given image data into transformation coefficients by subjecting this image data to a frequency decomposition, a dividing component which divides 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 which encodes the transformation coefficients by preferentially allocating a greater quantity of information to the selected region than to the non-selected region, and the dividing component performs an equation evaluation of numerical equation data that stipulates the boundary of the selected region, and determines whether the transformation coefficients belong to the selected region on the basis of the results of this equation evaluation, to perform the division into a selected region and non-selected region during image encoding with less processing.

Abstract: The present invention is intended to record image data having a wide dynamic range is a file together with image data having a narrow dynamic range. First, an image recording apparatus separately gradation-converts image data to be recorded into primary data having a narrow dynamic range and secondary data having a wide dynamic range. Then, the image recording apparatus calculates data that determines correlation between the primary data and secondary data and employs the calculated data as tertiary data. The image recording apparatus records the primary data and the tertiary data in a file. On the other hand, an image reproducing apparatus reads out primary data and tertiary data that were recorded in the above manner and reproduces secondary data having a wide dynamic range based on the primary data and the tertiary data.