How to cleverly apply Photoshop's image processing menu

Before printing, faced with a large number of originals sent by many customers, we found that some must use Photoshop for color correction. Using Photoshop software can adjust poor originals, which is the remedy taken when the quality of the original is poor. Here, the software used by the author is Photoshop 7.0.

Color preset

Before dealing with image manuscripts, it is important to understand the color presets in Photoshop software. Photoshop itself is capable of color management. Color presetting can be done in Photoshop. It is the color parameter of color space conversion. Its stability and unity are the basis for soft proofing.

1. RGB setting: The default value is “SRGB”. This option is suitable for images, screen display or webpage display, but it is not suitable for color printing. And "Color Match RGB" or "Adobe RGB (1998)" can be used for printing and publishing. The "Adobe RGB (1998)" setting is more suitable for prepress production. The screen contrast "Gamma", whiteness "White Point" and the screen three primary colors are automatically changed with the RGB setting.

2. CMYK settings: Photoshop's preset color separation conversion method (from RGB to CMYK) is generally using the default color separation table in Photoshop. After introducing digital proofing, our factory has established its own printing color management data for coated paper, offset paper and newsprint used in the printing back end. When adjusting the picture, different CMYK curves are called depending on the paper used for the back end printing.

3. Open the document settings: Here to determine how Photoshop set the color configuration, especially when opening the old document, often found that the description of the old document and Photoshop settings are different, the first option in the settings to determine the old document color settings still apply The second option allows the current document to apply the current color settings; the third option indicates that color management is not applied.

Image adjustment

The color setting is clear, and there is a purpose for the selection of the conversion in different situations. Let's talk about image adjustment applications in Photoshop, which can be roughly divided into the following steps.

1. Establish a characteristic curve from white field to black field. According to the results of the gray balance test in proofing and printing, the image adjustment is required to be consistent with the gray balance curve.

2. Check for errors in the scan. Select “Image/Adjustment/Curve” (shortcut Ctrl+M) to verify that the white field is balanced (white field gray balance C5, M3, Y3) and whether the black field is balanced (dark field gray balance C96, M88, Y88, K85).

3. Check if the picture is color cast and see if the data from neutral white to neutral black is correct.

4. Select “Window/Display Channels” to open the black channel in the channel panel to analyze the black-tone tone and data. Select “Curve” and “Layer” respectively under “Image/Adjustment” to adjust the Black Edition. Tone.

The usage of the black edition is such that when using the C, M and Y three-color editions as the main ones in the normal traditional separation situation, the black edition is the auxiliary, and the black edition uses the short pitch black, and the compensation cannot be made pure by the three-color overlay. Black deficiency. The other uses GCR color separation, with the black version as the main and the tri-color as the auxiliary, replacing the grey and near-gray components consisting of the superposition of C, M and Y from the high light to the dark tone with the equivalent black. Compensate for the black ink and use the long black version.

It should be emphasized here that the black version plays an extremely important role in the color application of the picture. It is the basis of the entire picture skeleton, level, and spirit. The black tone can be handled well to make the picture level clear, colorful, and strong three-dimensional. . The improper handling of the black-tone tone makes the picture dark and unclear, and the color levels do not reflect it.

Normally the color of the original is scanned after scanning because some poorer originals are not sufficient for color correction in scanning. According to the actual situation, before adjusting the manuscripts, various types of manuscripts need to be categorized: reflection, transmission, material discs, and digital images downloaded online; skin color, scenery, metal, jewelry, morning glow, sunset glow, etc. Throughout, you know what to do.

1. Original manuscripts based on landscapes should be first layered and removed as much as possible. Because the composition of landscape ash is relatively small, primary colors should be the primary colors, and the black version should only be used as a backdrop. Characteristic manuscripts, such as early morning glow, sunset, rainbow, and backlighting photography, must have some exaggerated atmosphere.

2. The main text of flowers, pay attention to the basic color, color saturation, bright. The proportion of contrasting colors cannot be set too low and should be kept between 18% and 25%. The black version should also be properly retained.

3. The man-made manuscript, try to use "image / adjustment / curve" to adjust the proportion of color, whenever the skin color is adjusted, if the dark field can not reach the gray balance, available "image / adjustment" "can be "Choose color" in the black block to compensate CMY's dark field gray balance, but should not be used too much, otherwise there will be a leakage phenomenon.

Use the gray block of the “Selectable Colors” menu to adjust the very poor, non-colored special originals. If you select gray balance adjustment near the gray point in the figure, the color in the figure will also be enriched. However, it should be used in combination with a variety of methods.

It is worth noting that the “optional color” function can only be used as a compensation, and the adjustment value should not be excessive, otherwise, the color correction overshoot phenomenon will occur. Even large adjustments can only be in the range of 0 to 100 (except for special originals).

4. For dark and medium-toned manuscripts, it is best to select “Image/Adjustment/Curve” and adjust it with an S-curve. When the document is photographed, the foreground is subject to excessive light, the color is very shallow, and the depth of field is It is very dark. For example, in a scene of indoor meetings, the figures of the rostrum are not clear because the flash index is not strong or influenced by the scene lighting. After the sigmoidal curve is used to draw the contrast, the required values ​​are carefully adjusted.

5. For boring manuscripts, select “Image/Adjustment/Curve” and drop 5% at 75% of the curve, or drop a color curve of a certain color separately. When adjusting, balance must be achieved. In other words, use the “Image/Adjustment/Hue/Saturation” function to adjust the hue, brightness, and saturation, and adjust the value within 5.

Complementary adjustment of color-originated manuscripts with color balance: C, M, Y, R, G, B adjustment values ​​are within 15 and affect the value change from 2% to 3%. Use the brightening highlight curve steepness to adjust the flat and gray. Or the original with low contrast, the original high-gloss grayscale, generally about 10%, can be adjusted to 10% to 3%, so that the light part of the light up.

6. With the RGB color mode curve, the originals downloaded from the Internet can be received with better results by adjusting originals with large color casts, originals with medium pitch, dark manuscripts, or originals taken with a digital camera. This is because the color space of the RGB mode is composed of an additive method and has a wide color gamut, and it is easy to visually feel the effect of color change. With color perception, convert to CMYK color mode for fine-tuning.

7. For the underexposed image in the picture, you can use the following method to adjust: execute the “image/copy” command, copy a new file, change to grayscale mode, set with Gaussian blur, the value is 3-6. Return to the original file, use "select / load selection", select "grayscale" in the "channel"; select "inverted"; "operation" in the "new selection." Close the copy file, use the "Edit/Fill" command in the original file, select "50% Gray" in the "In Use" dialog box; select "Color Dodge" for "Mode" and set "Opacity" to "100%". Through the above steps, the picture can reach a substantially satisfactory exposure result.

8. Select “Image/Adjustment/Change” to adjust the adjusted color-rich originals, such as rainbow, morning glow, and sunset glow, to make them more plump, crisp, and thick. .

9. For thin originals, you can create a new layer in the "Layers" panel, extract 25% to 30%, and overlay it on the original in negative mode, which will increase the thickness.

In short, using Photoshop's "image" menu, starting from a variety of channels to operate, combined with scanning and computer application software, will do their best to improve production efficiency. By continuously summing up experience and mastering essentials in practice, operations can be quickly and easily handled and applied with ease.

Source: MEPHP.COM