Photoshop Selection Depth Exploration-extracting objects

6.4 Extract Objects

Some people like to use the [pull out] tool, but I don't like it. If you have mastered all of the previous selection tools, you can basically produce better (faster) image effects than the pull tool. When you cut complex objects, you can use the Extract tool in addition to the channel mask.

Before giving a thorough explanation of the [pull out] tool, let's talk about its basic operational steps. Please press this action on your own image. Requires the object to have hair, and the contrast with its background should not be too bright.

1. In order to protect the image, please back up its layer (COMMAND/CTRL-J) first. Because the extraction tool does not

is to obscure the unwanted part of the image, but to remove it.

2. To invoke the Extract tool, click the Filter/extract command (command/ctrl-option/alt-x). Use the highlight tool to draw around the edges of the object that will be drawn to display its edges in high light. The default color for highlights is green. Then change the width of the high optical device according to the type of edge transition. The extraction tool can find differences in contrast between the pixels in the selection background and the pixels in the foreground, so the high light portion must overlap the foreground and background areas on the edge, and must include the area within the transition line. Although a thick brush can easily (roughly) create a selection, it also creates more places to decorate. If the object reaches the edge of the canvas, there is no need to draw the edge contour. [Intelligent high light] can change the width of the high light, it is very suitable for processing the edges of the clear contour. If there is an operation error, please press the Option/alt key to switch to the [eraser] tool, erase the wrong place.

A

B

Figure 6.28 Source image (Legend a). To draw an object using the [high-light] tool in the Extract dialog box

The Edge (Legend B)

3. After the contour of the edge is painted, switch to the [paint bucket] tool, and then click inside the object to

Populate the selection. By default, the fill color is blue.

Figure 6.29 populating an object with the paint bucket tool

4. Preview: Check [extract] dialog box in the lower right corner of multiple options to be able to preview the extracted objects in different backgrounds

, and can display the object's highlights or fill effects, or switch between the source image and the extracted image.

Figure 6.30 the extracted object

5. Use the [clear] tool and the edge modifier tool to fine-tune and decorate the image. Only click [Preview]

button before you can use both of these tools. The clear tool reduces opacity, and multiple clicks can have cumulative effects. To restore the original opacity, press the Option/alt key. By increasing the opacity of the image, or by increasing the transparency of the background, the Edge decoration tool can sharpen the edges of the extracted object.

6. If you are satisfied with the results of the modification, click OK to return to the Extract dialog box.

To get the best results from the Extract tool, you also need to use the layer mask or alpha channel to do the following.

6.4.1 using the edges of the layer mask to fine-tune

Using the Extract modifier tool, you can correct the obvious problems with the extracted object and use the layer mask if you want to make further corrections. Action steps are as follows.

1. Perform the 1~6 step to copy the source layer and create the extraction object on the layer copy.

2. Press the Command/ctrl key and click the thumbnail of the layer to upload the transparency mask from the extract layer and convert the selection to a layer mask on the non-extracted layer. (if it is a background layer, press the Option/alt key and double-click its thumbnail to convert it to a normal layer.) )

3. After completing the above steps, remove the extraction layer.

4. Use the layer mask to fine-tune the edges as much as possible. Use the white painting to find the lost part

Come back; use the [blur] tool to paint on a layer mask, to selectively blur parts of the edges, and to use [levels] or [curves] to extend or block the mask.

A

B

Figure 6.31 The light layer below the image layer can expose the problem of the Edge (legend a). Smoke

The out layer is the basis for creating a layer mask (legend B)

6.4.2 uses alpha channels to extract objects

Here's an easy way to assemble the dual capabilities of the pen tool and the pull tool, and the designer is Russell Brown, an avid expert in Photoshop. If you want to display the edges of an object in high light, this method can completely replace the extraction tool, and it is more accurate than the former. Because the extraction of the high light can cause excessive or insufficient adjustment, if you use the alpha channel (derived from the pen path, the pen path can be drawn out of the basic shape of the object), you will be able to achieve more satisfactory results.

Figure 6.32 Source image (Legend a), extracted object (Legend B)

1. Before extracting the object, remember to back up the image, then draw the pen path around the object, and then double-click the work path thumbnail in the Path palette to store the path.

2. Copy layer (COMMAND/CTRL-J). Then add the diagram to the layer copy (not the extracted layer)

Layer masks.

3. Click the Create new channel icon at the bottom of the channel palette to create a new channel. This new channel

It's black. Set the foreground color to black, and then select the Brush tool. It has a diameter of 20 pixels and a hardness of 50%. Activate the storage path, and then click the Brush Stroke path icon at the bottom of the path palette.

4. Reversed-phase new channel (COMMAND/CTRL-I). At this point, the channel should be the shape of the extracted object whose body

Is white and has a black outline. This time, use this contour instead of pulling out the high light to define the object.

5. Thus, the image has a basic outline. Click the [Filter/extract] command (COMMAND/CT R L-

Option/alt-x), an Extract dialog box appears. In the dialog box, from the channel option

Drop-down menu, select [Alpha 1] as the outline. To extract the processing of an object, see "pumping

The 3rd to 6th step in the basic step of the Out object.

A

B

C

Figure 6.33 Strokes the path on the new layer (legend a), reverse the channel (legend B), and let it

Instead of a high-light tool (Legend C)

6. If you are satisfied with the extraction object, and then follow the 2nd to 4th step in the previous method (using the edge of the layer mask to fine-tune the edges), use the layer mask to further adjust the edge of the image.

Figure 6.34 Effect of the extracted object after being processed

6.5 Summary of this chapter

Channel masks are the best of all selection tools. It's the ones that sometimes seem to be impossible to handle. Every time you use it, you feel as if you've succeeded, at least in

That's how it is in Photoshop. Since each image is unique, there is no ready-made method,

There is no law of universal. But after using the channel mask, you will inevitably have the idea that it is the best tool in the job and that it is better than any other tool you might use. Typically, a channel mask is used if the image has a primary color, the edges are clear, and the edges are appropriately matched. If not, maybe you can use it to deal with some constituencies.

Category:

• PS Image Processing