Analysis of Photoshop interpolation and amplification image

Amplification

Many friends often ask how to enlarge a small picture. In fact, whether it is Photoshop, other image processing software, and some magnified image of the "special software", including digital camera "digital zoom", using the "interpolation" method to enlarge the image, the difference is only "interpolation" algorithm.

Let's take a look at the "interpolation" to enlarge what is going on.

What is interpolation?

interpolation (interpolation) is the operation method used in image redistribution of pixels, and also a mathematical process for determining intermediate values. When resampling, Photoshop uses a variety of complex methods to preserve the quality and detail of the original image.

What are the algorithms for Photoshop "interpolation"?

If we want to change the size of the image in Photoshop, perform the image > Image size command, in the Image Size dialog box, you can set the "interpolation" method used to change the image size.

The option that follows the "Reset image pixel" is a different interpolation algorithm option

Let's use an example to illustrate the following.

The following figure is the jump Tiger original image (note here we selected a pixel map), and the use of different interpolation algorithm to enlarge the original 200% effect.

The " proximity " method is fast but imprecise, and is suitable for images that need to retain hard edges, such as the scaling of pixel graphs. You can see that the feature of the pixel map is maintained very well.

" two-time linear " interpolation method for medium-quality image operation, faster.

The " two cubic " interpolation method allows the edge of the image to get the smoothest tonal level, but the speed is slower.

The two cubic cube (smoother)is applied to enlarge the image on the basis of two cubic cubes.

The " two Cubic cube (sharper)", which is based on the two cubic cubes, is suitable for the reduction of images to retain more detail after resampling.

If we want to preset the image's "interpolation" option, you can choose Photoshop's Menu "Edit > Preferences > General", set the image "interpolation" preset, when the setting is complete, the image uses the "Free transform" command to enlarge or shrink, using the preset "interpolation" mode.

If you find a good effect of "interpolation" to enlarge the image of the method, you may wish to share the message in the following article!