Photoshop Using layers for selections perfect
Today I would like to make a quick and effective solution to clip objects in Photoshop.
It is sometimes difficult to select images that I describe as "complex" such as hair, fur, or any other small details.
There are many methods to perform such tasks but I'll choose the RGB because it is my opinion, the most rapid and most versatile in the sense that they can be used to select any object type in almost any environment.
To illustrate this little tutorial I'll use a photograph of a spider (available here ) with fine hairs may seem rather tedious to clip one to one without the use of the RGB channels ... You can click on images to view full size.
's go!
When you open the image in Photoshop, you default on the window "Layers". You can see that the clipping of this animal is not necessarily straightforward even if it is facilitated by the white background. Zoom major highlights of many small details (like the bristles of the legs) it would be difficult to select with tools such as magic wand, or pen mode mask. I suggest you use the RGB to select our animals.
We'll click on the "Layers" to display the red, green and blue component image. For this work of selection using diapers, I suggest you opt for their display level of gray rather than color. To switch from one mode to another display go to "Edit"> "Preferences"> "Interface"> "Show Channels in Color", and uncheck the box to display the layers in grayscale.
When working with layers, the goal is to isolate the object that you want to select by increasing its contrast with the background. In our case, we're going to "fill" our spider with black color, while we make the background completely white. Thus, the contrast between the animal and the background will be a maximum, the selection will be almost perfect. In First, we'll look which of the 3 layers Red, Green or Blue, presents the greatest contrast between the spider and the bottom. We'll click successively on each of the 3 layers to see what happens. The image above is rendered depending on the selected layer.
Thus we see that it is on the Blue layer that the contrast is greatest. To avoid damage to our image, we will work on a copy of this layer. For this, either right click on the blue layer "Duplicate layer", or we slide the Blue layer on the icon of duplication (next to the trash). We now have a layer "Blue Print" at the bottom of the stack of layers.
Remember that the purpose of this work is to obtain an all-black spider on a white background. To further improve the contrast, we use a feature of Photoshop little known "Apply Image". The aim will be to merge layer "Blue Copy" on itself to increase its contrast. To apply merge operations on the layers, another option is to go through the "Operations" in Photoshop ("Images"> "Transactions").
After select "Apply Image" you must define which layer merge. For us it will be the layer "Blue Copy". And you must choose the operation to be applied, this corresponds to the blend modes. We will choose how best to improve the contrast of the animal. We will select the operation "product" because the result (directly visible in the preview) seems correct. You can now confirm by clicking OK. The color value of each pixel of the layer will be multiplied by itself. The result will be a darker layer. Attention, although some blending modes allow for maximum contrast, they will cause some loss of image detail. We must therefore find the best compromise between high contrast and preservation of image details.
looks like our picture after the product layer "Blue Copy" on itself. There are still some details to be corrected because the contrast is not perfect. Although it is difficult to realize on the screenshot above, the background is not completely white and parts of the animal longer pull on the dark gray than black. We'll use levels to improve the rendering.
To reveal levels: "Image"> "Settings" > "Levels" or Ctrl + L. To increase the contrast we'll drag the black slider to the right and move the white slider to the left. The image above shows the record you before and after. Even if it is not obvious on this screenshot, this correction operation through the levels is very effective when you use the layers to select your items.
After correction using levels, it will sometimes make minor corrections. In our case, we see that there is still relatively light on our spider. To correct this, take the brush (B), opacity 100%, size 15px, Hardness 100% "Normal" mode and in black paint on the white parts. Hint: To avoid damaging the parts already selected, use the mode "Soft Light" to reveal the black without damaging the white. Conversely, use the mode "Overlay" to reveal the white parts without changing the black. These two methods are very effective when you need to improve the contrast of a small detail of the image. We will use the brush in "Soft Light" to blacken a hair on a white background. In contrast we use the mode "Overlay" to whiten a light gray background without damaging the black layer.
After the passage of the brush, here's what our image looks like. At first sight it is! We have an almost perfect contrast. Now, remember that when we work on layers, the white parts represent the selected areas. As it stands, the selection will therefore our outline. So we have to invert the colors of the layers.
To reverse the colors, use the shortcut Ctrl + i ". Our spider goes white on black background.
Before recovering the selection, you can correct the details revealed by the reversal of colors. If you act in the middle of a large area black or white, use the brush (B) in normal, opacity 100%. However, if you need to paint the border zone between black and white area, choose the mode "soft light" or "pop" as if you paint an area of black or white (cf. paragraph above). Hint: here are 2 useful shortcuts when the brush (B) is selected: To be black as the foreground color is the key (D) to switch the black background and use white foreground is the (X).
Now that our contrast is perfect, we will transform our layer into a selection by clicking on the icon represented by a small dotted circle in the bottom of the Layers window. Make sure you click on the layer "Blue Copy" before to activate it.
The spider is now selected, we will reactivate the RGB channel, by clicking it. The image returns to the colors, the selection is always visible.
To use this selection, we must return to the window "Layers" (F7).
Now use the selection tool (M), go inside the selection and right click "Layer via Copy." Alternatively, move the background layer and use the shortcut: Ctrl + J. This will copy the spider trimmed on a new layer at the top of the stack. To better visualize the quality of the selection, you can create a new layer under the spider trimmed and fill with a bright color. I used pink to see the result. Hint: Sometimes it remains a fringe 1px around your selection. To correct this, go to "Layers"> "Cache"> "Remove Black Matte" or "Remove White Matte. This will remove the excess black or white around your object.
This tutorial is now complete, the goal was to highlight the power of the RGB channels to perform complex selections. If parts are not clear enough, feel free to email me for any further explanation. You can download the image used for the tutorial on the image bank "Stock X-Change" at: http://www.sxc.hu/photo/964417 . The techniques described in the article were highlighted by Scott Kelby, Photoshop trainer in the USA, editor of the magazine "Photoshop User" and president of the NAPP (National Association of Photoshop Professionals). Some links
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