Light through Blinds

The purpose of this photoshop tutorial is to imitate shadows on a person as if cast by window blinds. I will use a Displacement Map for this. I will also use Lab Color. If this sounds like Greek to you, just follow the steps, you will be able to understand.

I have opened this photo on which I will create the shadow of the blinds. I have switched over to Photoshop CS 3, but this tutorial can be done with any version.

Step 1 : Go to Image>Mode>Lab Color.

Step 2 : In the Layers/Channels/Paths pallette click on Channels.

Step 3 : Look at the Channels pallete which has opened. The channels are Lab, Lightness, a and b.

Step 4 : Click on the Lightness channel.

Step 5 : Notice that the image turns into black and white.

Step 6 : Now right click the Lightness channel. A small dialogue box appears with the options of Duplicate Channel and Delete Channel. Select Duplicate channel.

Step 7 : From the 'Name' select 'New'. Click ok.

Notice that a duplicate image has formed.

Step 8 : Press CTRL+L on the keyboard. This will bring up the Levels dialogue box.

Step 9 : Drag the black and the white sliders inwards to increase the contrast and click ok.

The contrast has increased.

Step 10 : Choose the Magnetic Lasso Tool or the Pen Tool, whichever you find convenient to handle.

Step 11 : I have selected all the background except the girl. You can see the column of marching ants that make up the selections shown by the red arrows.

Step 12 : Press SHIFT+F5 on the keyboard which will bring up the Fill dialogue box. From the dropdown choose 'Use' as White. Make sure that the Mode option is set to Normal and Opacity to 100 % and click ok.

Step 13 : The background of the image has been filled with White. Press CTRL+D to delect. The marching ants will disappear.

Step 14 : Go the Filter>Blur>Gaussian Blur.

Step 15 : The Gaussian Blur dialogue box opens. I have set it to 4.0 pixels. There is nothing hard and fast about it. It will depend on your image. Click ok.

Step 16 : The image has now blurred slightly with the Gaussian Blur applied.

Step 17 : Go to File>Save As

Step 18 : I will save the image as psd naming it woman. I will save it in My pictures. I will use this image for a Displacement Map. A displacement map is a black and white image which Photoshop uses to determine how to move and reposition pixels. Now close the duplicate image as it has been saved.
Step 19 : Now to convert the image back to RGB color. Go to Image>Mode>RGB.

The image has changed back to color.

Step 20 : Click on the Add New Layer icon shown by the small white hand and a New Layer i.e. Layer 1 forms above the 'Background'.

Step 21 : Click the Rectangular Marquee Tool.

Step 22 : Draw out a narrow rectangle as shown above. These will be the bars of the blind.

Step 23 : Press SHIFT+F5 to bring up the Fill dialogue box again. From the dropdown choose Black for 'Use'. Click ok.

The selection has been filled with Black.
Step 24 : Select the Move Tool.

Step 25 : Press ALT on the keyboard as well as SHIFT and drag down with the Move Tool. You will find a duplicate selection. Keeping the SHIFT key pressed ensures that you drag down vertically.

Step 26 : I have added another black selection in the same way. Continue this.
Step 27 : I have added all the bars in exactly the same way.

Step 28 : Look in the Layers/Channels/Paths pallete and you will find the layer with all the bars in Layer 1. Press CTRL+D to deselect.

Step 29 : Go to Filter>Blur>Gaussian Blur.

Step 30 : I have set a Radius of 9.5 pixels by dragging the slider. You can set it as you please. Click ok after you are satisfied with the result.
The bars have become blurred.

Step 31 : Go to Filter>Distort>Displace.

Step 32 : The Displace dialogue box opens. Set the Horizontal Scale at 0 and Vertical Scale at 20. Make sure Stretch to Fit and Repeat Edge Pixels are selected. Click ok.
Step 33 : Photoshop now opens 'Choose a Displacement Map' dialogue box. I had saved the Displacement Map as woman. And there it is.
Step 34 : The Displacment Map has been applied. I have in fact applied it twice. The Displacement ensures that the bars wrap around the contours of the girl realistically.

Step 35 : In the Layers/Channels/Paths pallette lower the Opacity suitably by dragging the Opacity slider to the left.

The Opacity has been lowered. The shadows fall across the body realistically moulding with the curves.

Step 36 : Click the New Fill or Adjustment Layer button.

Step 37 : From the popup click on Color Balance.

Step 38 : The Color Balance dialogue box opens. Select Shadows and drag the Cyan-Red, Magenta-Green and Yellow Blue sliders as shown. Do not click ok.

Step 39 : Now select the Midtones and drag the Red slider as shown. Now click ok.

The finished image. Notice that the bars in the background are perfectly straight, while the portion falling on the body has bent with the contours of the body. That was because of the use of the Displacement Map. That is all. Try it out.