An inkjet printing apparatus includes an edge detecting unit adapted to detect an edge portion and a non-edge portion in the image data; a memory adapted to store a plurality of edge reducing masks used to reduce image data in the edge portion and a plurality of non-edge reducing masks used to reduce image data in the non-edge portion; a reduced data generating unit adapted to generate multiple sets of edge reduced data from image data in the edge portion using the plurality of edge reducing masks and to generate multiple sets of non-edge reduced data from image data in the non-edge portion using the plurality of non-edge reducing masks; and a printing data generating unit adapted to generate multiple sets of printing data by combining the multiple sets of edge reduced data and the multiple sets of non-edge reduced data.

An inkjet recording apparatus for recording an image on a recording medium, including a recording head, a drive circuit and a control device. The head includes an ink passage, a nozzle communicated with the passage, an actuator applying energy to ink in the passage to eject a droplet of the ink from the nozzle onto the medium. The drive circuit outputs a signal for driving the actuator to eject the ink droplet such that at least three ink droplets are ejected for printing one dot. The control device controls operation of the circuit and includes a high-temperature control portion and a low-temperature control portion. The former portion operates, in a first case where an environmental temperature is higher than a threshold, to control the circuit to output a first kind of the signal according to which a dot is formed by a number of ink droplets ejected in series and landing on the medium sequentially in the order of ejection. The latter portion operates, in a second case where the environmental temperature is not higher than the threshold, to control the circuit to output a second kind of the signal according to which a dot is formed by the same number of ink droplets as in the first case. A total ink volume of the droplets ejected according to the second kind signal is smaller than that according to the first kind signal.

A total-ink method ensures that the total amount of available colors remains the same such that the color characterization process can treat the restricted printing process as if it is dealing with a non-restricted printing process without loss of quality. This method enhances non-lossless, black generation methods traditionally used for total-ink restriction by generating compensated target device contone image data in which colorant applied to the media is limited based on a total ink constraint by providing a one-to-one mapping between each possible input contone image data value and each possible compensated target device contone image data value, using a bijective function, for example.