Lenticular printing tutoria
--Converting a 2D picture to a 3D Lenticular Print using PSDto3D

We now combine with stereo image processing examples,introducing a three dimensional image processing method.

In this example, an image to be processed is a picture of a hot air balloon image, has a clear three-dimensional sense, suitable for stereoscopic processing, as shown in figure 1.1.

Image 1.1

① Open the original image in the Photoshop , check the image size, its size as shown in figure 1.2.

Image 1.2

Due to its resolution does not meet the requirements, needs to be modified for the resolution of 75.55 × 8=604.4lpi. But this time the document size is very small, so the document size is adjusted for high 6cm, width 8cm, then the size of the image data as shown in figure 1.3.

Image 1.3

② Mark the images of various parts of the stratification. It is divided into 8 layers, as
illustrated in figure 1.4.

Image 1.4

③ Separate those marked parts .
Use the pen tool to do the image matting, each balloon is selected, then cut; click on button on the lower right corner to create a new layer, and then paste those clipped layers to a new layer.
See the picture of original image after separating one layer ,as shown in figure 1.5.

Image 1.5

The clipped part is separated into a new layer, as shown in figure 1.6.

Image 1.6

Separate other layers according to the process above. Eventually all the layers are separated to the corresponding layer.
④ After all the layers are layed, the background will be incomplete, as shown in figure 1.7.

Image 1.7

Because in the 3d stereo image, each layer in stereoscopic display will be of left and right displacement. Therefore, in the background , the blank area will be displayed. It is not reasonable, so it needs to complement the blank area.
　　　
The method to complement graph is to use the rubber stamp tool. Paste the other similar image to the blank area. In this way,the viewer would not see the unreasonable blank graph,even if the layer has displacement .The effect after complementing graph as shown in figure 1.8.

Image 1.8

Saved as PSD format, ready for further process by Psdto3D .

4.2 Post processing for stereo image
① Import the image above (PSD format) into Psdto3D software, the overall situation as shown in figure 1.9.

Image 1.9

Imported image parameters as shown in figure 1.10.

Image 1.10

The grating and a lens are not consistent with the actual data. Upon the determination, the actual raster resolution is 75.55lpi, so the grating will be changed into 75.55lpi , lens will be replaced in 8, focus and depth keep the same.

②Set the displacement value for each layer . When the above settings are adjusted, a displacement will be automatically generated . You can adjust a little as per the effect .The result is as shown in figure 1.11.

Image 1.11

③ Hook line for each single layer. preview the single layer after each end of hooking line for every layer . The hook line results as shown in figure 1.12.

Image 1.12

④ After each layer being hooked line, observe effects combining with the preview , and make adjustment to achieve a desired effect . Preview the results as shown in figure 1.13.

Image 1.13

⑤ Output the final three-dimensional image. The image is derived as shown in figure 1.14.

Image 1.14

Now, we have finished the process of 2D to 3D conversion . Output the image to a paper, covered with the grating, and you can achieve the stereo sense on the vision.

Important technical information about lenticular printing 

① In the Photoshop, in the original image parameter setting and adjustment, It should be strictly in accordance with the grating resolution number multiplied by lens number. Through strict measurement, the grating resolution actual resolution is 75.55lpi, so the resolution of the image should be set to 75.55× 8=604.4lpi.

②The order of layer also should be payed attention. After stratification,in the Photoshop the layer display column from top to bottom shows all layers. At this time from top to bottom of the order, it should be the same with that of in the original image from front to back along the line. Because the layer in the first layer is in the front of other layers, if the arrangement of above and below did not keep consistent with the order of front and behind , it needs to drag each layer to be adjusted in the layers display column .　

③ During the process of setting,to set a proper lens number is also very important. In theory, the more lens number, the more better effect you will get for 3D effect. It is just like the animation image frames, the more frames, the human eye in watched less prone to skipping phenomenon, the more fluent you will see. But because of the existing various types of printers, printer output devices such as precision ,it is hard to meet the precision requirements of the image.
Here in 200Lpi grating material for example: through the computation,we know the grating spacing is 0.127mm. If the lens number is set to 8, it is equivalent to the 0.127mm compress 8 images, so,a single image with an accuracy of 0.127 / 8= 0.016mm. If it was a 30 lens ,its precision will be achieved 0.127 / 30=0.004mm. Such a high accuracy , the existing equipment can not meet. Therefore, in the processing of stereoscopic printing image, it needs to find out the highest accuracy of printing output equipment to calculate the maximum number of lens,while the existing manufacturers generally uses 6 ～10 lens number. So,in this example,we take these factors into account, seting lens number tobe 8.

④ Among all those layers, layers are in sequence. In order to realize the three-dimensional effect, we need to fix a layer as the medium. In vision, the layer in the middle distance position is identified as the medium. The medium shot is no displacement.

⑤ Import the PSD image into Psdto3D soffware, and set the parameters, then the software will automatically generate a default displacement. But this displacement may not be able to achieve the best effect, it should be properly adjusted, until the best effect.

⑥ When hook the single layer, we need to Keep coordination for the line and graph contour .