Abstract: An apparatus for printing video images is disclosed. First the percentage of backlighting or people in the image is detected. That is, the probability of the presence of backlighting or people is detected. Then, the density gradation table is modified based on the detection result, and the presence of backlighting or the presence of people in the image is evaluated based on optical information, to select the best density gradation table from among plural density gradation tables, or to synthesize the best density gradation table. A luminance table is generated using the optimized density gradation table, and gradation correction of the image is then accomplished using that luminance table.

Abstract: In the disclosed thermal gradation printing apparatus, heat elements in a line-type thermal head are divided into a plurality of groups, and an accumulated heat amount in the substrate of the thermal head for each group is estimated based on the pulse width data applied to each heat element considering the influences by heat accumulations in the main-scanning direction and in the sub-scanning direction. Based on the group division estimated accumulated heat amounts and the temperature of the body portion of the thermal head, a correction value for the pulse width data to be applied to each heat element. Moreover, the correction value is applied to the pulse width data for each heat element, so as to output the corrected pulse width data to the thermal head.

Abstract: In an image data including tone information, a level of an attentional picture element in an image and a level of an adjacent picture element located adjacent to the attentional picture element are smoothed to create a first substitution level, and by internally dividing the level of the attentional picture element and the first substitution level with a predetermined internal division ratio to obtain a second substitution level which finally substitutes the level of the attentional picture element.

Abstract: A font data output method that applies bandwidth limitation to binary font data using a two-dimensional low-pass filter, and applies gain of one or more to a multilevel-value data group obtained by reduction at a predetermined ratio according to the distribution of values in the multilevel-value data group to generate the gradated font data. Using this method, the loss of line and character density in the font data due to a high reduction ratio can be prevented.

Abstract: In interpolation lines having plural angles passing through an attentional pixel on a scanning line in one field to be interpolated having pixels on an upper scanning line placed over the attentional pixel and pixels on a lower scanning line placed under the attentional pixel, a horizontal spatial frequency is detected in the vicinity of the attentional pixel to be interpolated, interpolation directions are derived by plural interpolation direction decision steps on the basis of obtained spatial frequency information, and the scanning line is interpolated by selecting one direction of the plural interpolation directions.

Abstract: An apparatus for printing video images is disclosed. First the percentage of backlighting or people in the image is detected. That is, the probability of the presence of backlighting or people is detected. Then, the density gradation table is modified based on the detection result, and the presence of backlighting or the presence of people in the image is evaluated based on optical information, to select the best density gradation table from among plural density gradation tables, or to synthesize the best density gradation table. A luminance table is generated using the optimized density gradation table, and gradation correction of the image is then accomplished using that luminance table.

Abstract: A level difference of an upper pixel on an upper scanning line placed over an attentional pixel and a lower pixel on a lower scanning line placed under the attentional pixel, a level difference of the upper pixel and a lower left pixel, a level difference of the upper pixel and a lower right pixel, and a level difference of the lower pixel and an upper left pixel and a level difference of the lower pixel and an upper right pixel are derived. These level differences are compared with each other, and a line having a smallest level difference is detected and an effective interpolation line information is generated. Moreover, the level difference of the upper pixel and lower pixel is compared with the level difference of the upper right pixel and lower left pixel, and a smaller is set as a first interpolation line.

Abstract: The present invention provides color conversion apparatus that prevents overflow in color reproduction, changes in hue, and the deterioration of gradation to improve image quality. The present color conversion apparatus inputs to itself luminance and color difference signals, sets a reference value not less than the maximum level of the luminance signal, converts the luminance and color difference signals into primary color signals, detects the maximum value of the primary color signals for each pixel, lowers the levels of the color difference signals if the maximum value is over the reference value to locate the amplitude of the primary color signals not greater than the reference value.

Abstract: The gradation correction device includes a luminance signal convertor to generate a luminance signal from the input R, G, B signals, a correction coefficient calculator which calculates the ratio to the luminance signal of the luminance signal after gamma correction to the predetermined gradation characteristics, and a multipliers to multiply the output from the correction coefficient calculator by each of the R, G, and B input signals. When the gradation correction is applied, effective brightness adjustment can be applied with no change in hue and saturation and without exceeding the dynamic range of a device.

Abstract: In the disclosed thermal gradation printing apparatus, heat elements in a line-type thermal head are divided into a plurality of groups, and an accumulated heat amount in the substrate of the thermal head for each group is estimated based on the pulse width data applied to each heat element considering the influences by heat accumulations in the main-scanning direction and in the sub-scanning direction. Based on the group division estimated accumulated heat amounts and the temperature of the body portion of the thermal head, a correction value for the pulse width data to be applied to each heat element. Moreover, the correction value is applied to the pulse width data for each heat element, so as to output the corrected pulse width data to the thermal head.

Abstract: The present invention provides color conversion apparatus that prevents overflow in color reproduction, changes in hue, and the deterioration of gradation to improve image quality. The present color conversion apparatus inputs to itself luminance and color difference signals, sets a reference value not less than the maximum level of the luminance signal, converts the luminance and color difference signals into primary color signals, detects the maximum value of the primary color signals for each pixel, lowers the levels of the color difference signals if the maximum value is over the reference value to locate the amplitude of the primary color signals not greater than the reference value.

Abstract: The present invention discloses a missing pixels interpolating method and an apparatus using the method. The method forms a second image from a first image by interpolating a plurality of pixels constituting the first image with a plurality of first pseudo-pixels in such a way that they neighbor to the pixels diagonally and with a plurality of second pseudo-pixels in such a way that they neighbor to the pixels vertically and horizontally. The method comprises the first process of computing values of the first pseudo-pixels using a first monotonous increasing non-linear function, and the second process of computing values of the second pseudo-pixels using a second monotonous increasing non-linear function.

Abstract: A data recording medium using a format that includes: a data zone having a plurality of bands composed of at least one track, in which user data are written; and a control zone in which band control data are written. Each of the band control data corresponds to a respective one of the plurality of bands. The band control data are independent from each other. The band control data include read control data for a READ operation and write control data for a WRITE operation, which are independent from each other.

Abstract: An image data processing apparatus for generating a font with contour lines expressed with gradations comprises a font ROM for storing a binary font data. An output port is provided for reading a target pixel with ambient pixels arranged in 3.times.3 matrix of the binary font data stored in the font ROM. A shift register produces an address data based on the binary data read from the font ROM. A look-up table has 2.sup.3.times.3 elements in which multilevel values in commensurate with the pixel patterns included the 3.times.3 matrix. One data of the multilevel data is output from the look-up table by designating one element by said address data, and is used as a gradation data of the target pixel. Thus, pixel of font can be expressed with a gradation, the jagged contour of the font is reduced.

Abstract: Luminance data Y(1) (i=1,2, - - - ,n, - - - ) are input one by one to a detecting unit, and luminance correlation information R(i-1,i) denoting a luminance correlation or a luminance non-correlation between the luminance data Y(i) and Y(i-1) are generated. Four pieces of luminance correlation information R(n-1,n) to R(n+2,n+3) are stored in a filter controlling unit. Also, chrominance data C(i) are input one by one to a starting-stage chrominance data generating unit, and starting-stage chrominance data C1(n+2) is generated from the chrominance data C(n+1), C(n+2) and C(n+3) according to the luminance correlation information R(n+1,n+2) and R(n+2,n+3). other starting-stage chrominance data C1(n) and C(n+1) are generated in advance in the same manner. Second-stage chrominance data C2(n+1) is generated from the starting-stage chrominance data C(n), C(n+1) and C(n+2) in a second-stage chrominance data generating unit according to the luminance correlation information R(n,n+1) and R(n+1,n+2).

Abstract: A printer for recording a multitone image in which pulse width correction data is generated based on a temperature output of a thermistor for detecting the temperature of a head mount of a thermal head and an output of a data cumulating circuit for cumulating pulse width data inputted to the thermal head; and an adding circuit which adds the pulse width data to an output obtained by conversion, from inputted tone data, made by a .gamma. correcting circuit, thus accomplishing a temperature compensation. The temperature compensation constants necessary for calculating pulse width correction data are also determined.

Abstract: Disclosed is a clock distributing apparatus for distributing clock signals with a desired phase to each of devices provided between a clock generating section (10) for generating clock signals and a plurality of devices (30) for receiving the clock signals. A delay generating section (21) generates a plurality of delay clock signals by imparting a plurality of delay quantities to the clock signals from the clock generating section. A clock distributing section (22) has a plurality of input terminals corresponding to the plurality of delay clock signals and a plurality of output terminals corresponding to the respective devices. The clock distributing section (22) distributes desired delay clock signals to one or more output terminals by selecting the input terminals corresponding to the desired delay clock signals.

Abstract: Interpolation method and apparatus for interpolating pixels using levels of pixels surrounding a pixel to be interpolated is disclosed whereina level difference between two pixels on an interpolation line is calculated for all interpolation lines, likelihoods of correlation are calculated from the level differences obtained using a membership function,an interpolation direction is determined based on the likelihoods of correlation and directions of the interpolation lines and an interpolation value for the pixel to be interpolated is calculated based on levels of two pixels on the interpolation line having the interpolation direction determined.

Abstract: According to the present invention, when a current system is switched to a spare system in a transmission system in an asynchronous transfer mode, empty cells transmitted in the current and spare systems are detected, and thereby a timing for switching the current system to the spare system is determined. When no phase difference is existent between the current and spare systems, an empty cell is detected in both the current and spare systems at the same time. Therefore, the current system is switched to the spare system, when an empty cell is detected in both the current and spare systems at the same time. When a shade difference is existent, if an empty cell is detected either in the current or spare systems, another empty cell is inserted in to the systems. Then, the data of the empty cell in a spare system is saved. After the empty cell in a current system passes, the current system is switched to the spare system.

Abstract: A white balance coefficient setting unit 51 sets a white balance coefficient for an image signal; a white balance correction coefficient determination unit 52 determines two white balance correction coefficients to be applied to a luminance signal of the image signal in accordance with the white balance coefficient; a luminance signal operation unit 59 obtains two output signals by multiplying the luminance signal by each of the two white balance correction coefficients; a first adder 57 adds one of the two output signals and a first color difference signal of the image signal together; a second adder 58 adds the other output signal and a second color difference signal of the image signal together. Adding results of the first and the second adders 58 and 59 will be output as a white balance correction value to be applied to the two color difference signals.