subject: Color Management: How to do a major adjustment of pre-press printing - color management, pre-press - printing industry [print this page] Color Management: How to do a major adjustment of pre-press printing - color management, pre-press - printing industry
Four-color printed manuscript requires power points to plate. Separation of the original Apple has Fanshe Gao (such as: color pictures, drawings, watercolors, oil painting, Chinese painting, paintings, watercolor paintings, etc.) and the transmission is issued (such as: color reversal film (natural color positive film), color negative, etc.). Color negative originals on the brightness of the original scene contrast, color and complement the original features.
Four-color printed manuscript requires power points to plate. Separation of the original Apple has Fanshe Gao (such as: color pictures, drawings, watercolors, oil painting, Chinese painting, paintings, watercolor paintings, etc.) and the transmission is issued (such as: color reversal film (natural color positive film), color negative, etc.). Color negative originals on the brightness of the original scene contrast, color and complement the original features. Such as: negative on the opposite of magenta complementary color is green; yellow complementary contrast color for the blue-violet; red's complementary color to green the opposite. Positive on the original brightness of the original features the same color are exactly the same thing with the original Virtual.
Printed copy is in the transmission of light transmission is issued under the effect of the formation of visual images. The Fan Shegao irradiation in the light reflected from the original to form a visual image.
Print color tone is classified by shading, printing, copy work products to achieve color reduction, tone reduction, texture reduction, resolution reduction. Is hue accurate color reduction, copy print out a perfect reproduction of the real products color of the document, not color cast, no variegated.
Ideal means to restore original tone on tone printing products in the "faithful" to restore them to achieve the original copy requirements. Since the maximum print density was recorded 1.8, 1.8 after, it becomes a parallel to Dt (original density) of the straight line, so that both Fan Shegao draft transmission should be adjusted or the purpose of compression contrast, correct color, to tone suitable for print reproduction range.
Example: the highest color density of positive original Dt = 3.0, while the maximum recording density print Dr = 1.8.
Through the curve indicated that the print copy is not up to the highest density in the restored original, because the printed copy of materials used in the process, including ink, paper, photographic materials (film,
PS version ), Color order, and printing machinery and other constraints, the maximum recording density Dr = 1.8, but when Dt = 3.0, the maximum original density, contrast compression only, or no practical effect will be printed.
Print reduction in tone tone often need to make adjustments. When the original density contrast is greater than the maximum recording density printed, in order to make all the original tone can be expressed in print, it must be emphasized to restore order to make appropriate adjustments. Secondly, in order to meet the original copy of some special requirements (such as: bright tone mainly photo-based pictures of shadows), must be some original tone appropriate emphasis, and the corresponding compression of other tone. The main features of the linear compression is proportional section of the tone adjustment, linear compression does not truly represent the visual compression ratio such as D-Y curve is nonlinear, subject to such a compressed, bright mediation is not easy to distinguish the human eye, resulting in "gray level" phenomenon.
Tone of the copy refers to the percentage of original density and the relationship between the replication network.
Make the original all-order harmonic colors can now print on the surface very well, first of all choose the correct level curve. Level is the change in order to reconcile the basis of color, if the screen level is not rich, color performance is bound to be monotonous, and only level of realism, can have dramatic color changes.
Absolutely faithful copy original is impossible, because most of the original density contrast is greater than the density contrast between the print, it is bound to printed copy of the density compression. So it would lose some of the subtle level, in practice should be based upon the contrast and tone of the specific content of the reasonable adjustment of the level curve, that should be it Fan Shegao, or transmission draft position above the level of secondary compressed, so that the level of the main parts to focus on characteristics of the stress.
Contrast in color is issued subject to the normal, according to the different types of original curve of the right to adjust the level. Used electric extension and color separation on the level of control Apple is both convenient and flexible. It can enhance or partial compression, however, must pay attention to color separations level balance curve, the neutral gray balance to be appropriate and will not copy the correct level of curve distortion.
