tailieunhanh - Photoshop cs5 by steve Johnson part 30

Tìm hiểu về các chế độ màu màu kép Các màu kép màu chế độ chuyển đổi một hình ảnh thang độ xám thành một đơn điệu (1-màu), màu kép (2-màu), tritone (3-màu), hoặc quadtone hình ảnh (4-màu) bằng cách sử dụng 1-4 mực tùy chỉnh. Duotones thường được dùng để tăng độ sâu âm của một hình ảnh đen trắng. Ví dụ, máy ép in hầu hết sản xuất 50 cấp độ của màu xám cho mỗi | Understanding the Duotone Color Mode The Duotone Color mode converts a grayscale image into a monotone 1-color duotone 2-color tritone 3-color or quadtone 4-color image using 1 to 4 custom inks. Duotones are frequently used to increase the tonal depth of a grayscale image. For example most printing presses produce 50 levels of gray per color. By converting an image into a duotone and using black and a mid-gray value the press can produce a grayscale image with more dynamic range. A more common method for employing the Duotone color mode is to create an image with an overall color cast for example by converting the grays in the image to a sepia tone. If you re uncertain how to create the proper color mix for a duotone image Photoshop comes equipped with dozens of sample duotone tritone and quadtone color presets. Convert an Image to Duotone Open an image. Click the Image menu point to Mode and then click Duotone. IMPORTANT Before converting an image into a duotone it must first be in the Grayscale color mode. Choose from duotone presets available in the Preset drop-down menu. Choose to save or load a preset by clicking on the menu options triangle to the right of the preset menu. Click the Type list arrow and then select from the following options Monotone. Uses one color to generate image tone limited dynamic range . Duotone. Uses two colors to generate image tone better dynamic range for B W images . Tritone. Uses three colors to generate image tone. Quadtone. Uses four colors to generate image tone. Click the Overprint Colors button to adjust how the colors will display when the inks are printed. Q Click OK. Duotone color mode Q 0 0 Chapter 8 Understanding Colors and Channels 187 Using Multichannel Color Mode The Multichannel color mode is a specialized mode that converts the original color channels into shades of gray with the grays based on the luminosity values of the original image. The original channels are converted into spot colors. Since Multichannel mode