After the emergence of color inkjet printers, the type of ink is always the only important indicator to measure the performance of color performance, from four-color, six-color to the current eight-color printing, each increase in the type of color, print images, especially digital photos Print quality has reached a new level. In the era of HP Eight Color Printing, the number of colors directly obtained by digital photo printers has reached 72.9 million. The dramatic increase in the quality of color photo prints has made HP and other home and commercial printer manufacturers more and more confident to promote digital photo printing to professional areas, no longer limited to the home market, especially in the HP "eight color printing" professional digital photo After the introduction of the printer HP Photosmart 7960, eight colors became a favorite for photographers, enthusiasts and other professionals. At this time, the "any" way to increase the ink type to improve the print quality has also been more demanding from professionals.
Professionals believe that color is a three-dimensional color space, that is to say the color gamut. If you increase the color of ink arbitrarily, it will not have a revolutionary effect on the color representation of digital photos. To develop in the direction of increasing neutrality is the trend they recognize. Professionally, the color gamut is constructed from three independent and interdependent parameters: hue, lightness, and saturation. Hue is usually our visually sensitive saturated color, such as red, orange, yellow, green, blue, blue, and purple. With the improvement of ink and printing technology, the effect of color on the photo output has been difficult to produce a breakthrough. Because the human eye can distinguish between more than 150 kinds of hue in the spectrum, plus more than 30 kinds of extra-red magenta, about 180 kinds in total, the growth space is limited. If the existing colors of magenta, cyan, and yellow are increased, colors such as blue, green, and purple in the ink can only increase the saturation of the hue of the printed photograph, and the increase in the color gamut does not make much sense. Therefore, photography, printing, publishing, and other professional fields, invariably aim at improving the brightness of the direction, that is, by increasing the neutral color ink, showing more changes in the color light levels, so as to "geometric level Number" enhances color expression. HP digital photo printers have grown from six colors to eight colors. After adding dark gray and light gray neutral inks, the number of direct color types for digital photo printing has increased from 1.2 million to 72.9 million. "Lightness" promotes color gamut enhancement.
In color photography, printing, packaging, and other color applications, the change of light and shade occupies a very crucial position. The color or darkness of a photo or pattern is inflexible. It is inflexible, lacks three-dimensionality, and is not vivid, thus losing its authenticity. In general, the natural color performance in inkjet printing technology is to increase the level of color shades. If we look at the scientific model of the color gamut, the vertical axis in the color space represents the change in the brightness of the black and white series. The upper end is white, the lower end is black, and the middle is the transitional gray; the hue is represented by a circle in the water plane, on the circle. Each point represents a variety of different hues in the visible spectrum. From the current standard, the origin in hue can reach up to 180, and there are no more meanings. At this point, we can construct a color space. Each circle on the plane of hue, projected onto the vertical axis of lightness, will be given a "point" representing different colors. The color parameters of each point indicate the brightness, hue and Saturation three specific data, so that the formation of a three-dimensional color space. From the model, we can also see that the more neutral ash color, the more changes in lightness, the finer the color space is cut, and the more color types, the final result is a geometrical gamut. Number "expanded. Based on the principle of color gamut, HP introduced Furuto Pro's color grading technology to significantly improve the color performance of its eight-color ink printer. Accurate ink dot discharge, ultra-small ink droplets, intelligent distributed printing, etc., together with HP's unique halftone algorithm, enable the printer to obtain color by layering ink droplets according to the principle of color space. HP eight-color ink, black, magenta, cyan, yellow, to achieve a high saturation of hue printing, light magenta, light cyan plus new dark gray and light gray is rich in brightness changes, resulting in print color The domain has reached 72.9 million colors and is suitable for printing from professional color images to black-and-white photos.
In terms of color gamut management, the HP 8-color digital photo printer has added support for AdobeRGB with a wider color gamut in order to expand the color space. Traditional printing is designed for sRGB display color gamut. The color gamut range is far less than the natural color gamut seen by the human eye. Therefore, the printed photos are always unable to meet the strict requirements of professionals on color performance, and AdobeRGB is close to the human eye. The color gamut has become a color gamut standard for professional output peripherals such as printing, printing, and digital printing, and has been widely used. Therefore, when talking about how to increase the color gamut by increasing color, professionals emphasized that "the color gamut is not an arbitrary addition or subtraction of ink types," and the promotion of neutral inks can really achieve the goal of expanding color gamut.