Primer
Problems often arise from demand, and today this problem is no exception. I happened to encounter the problem of enlarging the picture. In an instant, I thought of two methods.
1. Stretch directly and sharpen. 2. Use ps cc2015 to stretch and retain details+manual correction.
Of course, the first method was rejected at first, and the second method proved to be inappropriate after many tests.
Put a beautiful picture:
There must be a way before the car gets to the mountain. I suddenly remembered the mysterious code forwarded by a group last month from the magic spike subtitle group to reprint the plate. The image quality of the DVD source residue has changed to the HD conscience image quality, which is said to be "using new suppression technology".
As we all know, video is also composed of static images of one frame, so this so-called "new suppression technology" is very interesting to me. So they began to inquire about the technical content they used, but they got nothing.
Coincidentally, I passed the text light novel game "す ぴ ぱ ら STORY # 01 – Spring Has Come!" last week, It is said that the OP of this game is the most expensive one in Japanese light novel games. Since the video extracted from the game file is only 480p, in order to live up to the eternal China Second News Agency, I searched the search engine for op+HD, and finally found the 900p OP reproduced by the player in a post bar.
According to the player, This is an OP video formed by stretching and resetting every frame with waifu2x and then compressing them together 。 After my comparison, I found that the effect of this 480p source image magnification can match that of HD animation, and both details and noise are perfect. When I searched this software, I accidentally found that Magic Spike was the user of this software. There is no way out after the mountains and rivers are over again.
Introduction to Waifu2x
Having said so much, it's time to get down to business. Today's introduction is the artifact Waifu2x, which allows you to have forced expansion or noise reduction pictures.
Different from general stretching, this algorithm is said to be generated by intelligent learning. Although I am a computer major, my code reading is almost zero, so I will not discuss the details of specific open source code, but only discuss its application effect.
1. Comparison of picture stretching effect
First, we select a 720p image (here we use the Goddess Alice extracted from sppl), and expand it by 2x (1440p) through the software and pscc respectively. Waifu is set as the default, and ps cc is set to retain details and add creases appropriately. They are 100% displayed and compared in the same display area. The results are as follows（ Pay attention to the hair, click the picture to enlarge it ）：
2. Waifu2x's handling of blurred pictures
Select a picture of 1.5x stretching by common method (the material used here is a picture of station p), and process it through waifu. The result is as follows（ Pay attention to lines ， Click the picture to enlarge it ）:
Pseudo multithreading test
I used a very stupid method: open two programs, and each program processes 4 pictures (8 in total), compared with the way of opening one program and processing 8 pictures in a queue. The results are shown below. I don't think there is much improvement.
summary
It can be seen from the above that in terms of zooming in and retaining details, waifu is really not a fake name. Under certain conditions, its generated pictures are even better than the original pictures.
When processing blurred images, waifu tends to Smooth lines , so it is more suitable for Quadratic metaimage 。
Due to the huge amount of computation, the processing time of waifu is much longer than that of pscc. Fortunately, some developers have developed a version that supports cuda acceleration, which is undoubtedly a blessing for n card users. According to network rumors, the processing speed of cuda is 70% faster than that of pure cpu.
As a five-year afan, I have no n card. In order to improve efficiency, I tested other versions and finally selected this one Both opencl and cuda versions are supported It is measured that the default configuration processing on the amd platform is about twice that of the pure cpu mode.
download
Provided here The version I am using (x64), please refer to readme.en (or readme.jp if you are good at Japanese) in the waifu2x folder for instructions. The use of waifu2x makes your outfit more layered, which may be the correct use of this device.
