Why print photos appear color error?

Color printers, scanners and their functional characteristics will be related to a color accuracy of the problem, and this problem often determines the quality of their image generation, product performance level, the size of the error ratio and other important indicators. Color accuracy refers to the proximity of the printer output or the color of the scanner input to the standard color.

RGB mode

We know that in the display, scanners, printers and other products, the use of RGB, CMY, HSB these commonly used color description and implementation methods, and thus achieve accurate output, the purpose of input color. Among them, RGB is the use of red R, green G, blue B combination of three colors to send different colors of light, monitors, projectors and other equipment, the principle of light and computer data storage principle is based on this color description method (In the computer, the color of each point on the image generally need to use a 24-bit RGB information stored, of which 8 for red, 8 for green, 8 for blue).

CMYK mode

CMY refers to the use of cyan C, red M and yellow Y combination of these three basic colors of color, people in order to enhance the effect of its pigment absorption, often coupled with black K (blacK) pigment, which is the formation of the current popular CMYK mode, so the color printer is usually based on the four color cartridges (some portable printers, due to volume constraints, will also use CMY three colors; six color or more color printer is increased by Light red, light green and other colors to make the color of printing more natural and improve the printing effect), it is also a color rendering method used in inkjet printers, prints and everyday use of pigment painting.

It can be seen because the three primary colors of light and physical reflection of the different color principle, will make the use of the computer to achieve the color of the method, and the computer will be the color output to the realization of the method will be different. In addition, the colors (Hue), Saturation (Saturation) and Brightness (Brightness) also play an important role in the performance of color, for example, the depth of each color, bright, glossy degree is determined by the HSB. Because the computer uses the RGB mode to display the page must be CMY mode (or CMYK mode) to print, which requires the color from RGB mode to CMY mode, and is responsible for the output color of the color printer, in this color conversion work, Its output color and CMYK mode standard color close to how, you can analyze the color accuracy of how it.

However, due to limited by the printer ink droplet size, print control, color ink quantity, brother ink quality and other factors, the use of the printer is difficult to print out the standard color, so in fact every printer has a certain degree of color deviation, Only good performance of the printer, the deviation of the human eye does not find it, but some poor quality of the printer, and the use of poor quality printer ink, the deviation will be more significant.