Chapter 1266

"The coffee is good." Liu Jinghui took another cup of coffee, drank it in one gulp, and then went back to verify the timeline.

Wei Shiyan looked at his appearance of not hearing anything outside the window, then turned to look at Jiang Yuan, who was thinking intently in front of the computer, and shook the hand-drip coffee with both arms again.

"Shiyan." Jiang Yuan suddenly looked up and called out.

"Ah! Master." Wei Shiyan immediately stepped forward.

Jiang Yuan examined Wei Shiyan for a moment and said: "I've looked at the practice problems you've done recently; there is still progress."

"Ah... it's because Master taught well." Wei Shiyan thanked himself and his senior sister in his heart for the days and nights they had spent together.

"Did you understand the steps I just took for image enhancement?" Jiang Yuan asked again.

"That's still a bit off." Wei Shiyan said with a sheepish laugh: "The steps are quite complex; I might need to learn for a while longer."

"You can try doing it." Jiang Yuan said, signaling Wei Shiyan to sit to the side.

A sensible local technician immediately moved a set of computer and monitor next to Wei Shiyan.

Wei Shiyan didn't even have time to object before the computer screen in front of him lit up.

He looked at Jiang Yuan on his left, then at the screen in front of him, feeling a bit like he was taking an exam next to the teacher.

"If you can't do it, just say so. You can try choosing a few more directions; you don't have to go down one path to the end." Jiang Yuan said, checking the software on the computer, and then threw a few video clips to him.

Wei Shiyan said hesitantly: "My math hasn't improved much either..."

"If you know how to use the software, you can use it. Whether you can upgrade, we'll see about your talent later." Jiang Yuan waved his hand, signaling Wei Shiyan to go into battle.

Wei Shiyan nodded with difficulty, like a sensible golden snub-nosed monkey, carefully opening an original video, making a backup first, and performing a hash value verification.

Next, after determining the video format, Wei Shiyan began to pre-process the video. First, he used Neat-Video for noise reduction, trying to remove grain noise or compression artifacts as much as possible, then performed multi-frame averaging for temporal noise reduction, Gaussian filtering and median filtering for spatial noise reduction. During this period, although the software was doing the work, just filling in the various values made Wei Shiyan's brain a bit overloaded.

He peeked at Jiang Yuan and saw that during the process of scanning the surveillance video, whenever he encountered a problem, he would just call up the software and tap a few times, and many values were in a state of rapid modification.

Those who don't know the trade might think Jiang Yuan is in a state of being a skilled worker; only Wei Shiyan knows that Jiang Yuan is in a state of skilled calculation.

Just like an ordinary person knows that sin 45 degrees equals the square root of two over two, approximately 0.707, the common value for the standard deviation of Gaussian noise in low-light surveillance is 1.5 to 2. But when you want to preserve edges, you can take a value of 1.0, or switch to bilateral filtering. But in many cases, you need to borrow the GaussianBlur function and calculate it based on the kernel size...

Compared to before, Wei Shiyan has understood many principles, but Gaussian noise is just a small step in the pre-processing steps...

A few hours passed in a flash.

During the break, Jiang Yuan finally remembered Wei Shiyan, so he paced over like a school teacher. He saw two computer screens in front of Wei Shiyan, the screens were bright, the cursor was flashing, and Wei Shiyan's eyes were open, and that was all.

"Hit a bottleneck?" Jiang Yuan asked gently.

Since he had accepted the second-generation task, he still had to do it.

Wei Shiyan looked up at Jiang Yuan blankly, then shook violently and said: "A lot of bottlenecks."

"Where did you get to..." Jiang Yuan wasn't in a hurry either. He himself was a cheater, so he knew even better the difficulty of image investigation. This thing belongs to the technology that normal people will become abnormal if they touch it. Fortunately, Wei Shiyan wasn't too normal to begin with.

Wei Shiyan looked up shamefully: "I wanted to remove motion blur, thinking of using Wiener filtering, but it turned into a mess..."

"Then use blind deconvolution, use focus-magic, I'll teach you how to adjust it." Jiang Yuan stood behind Wei Shiyan and taught him bit by bit.

Several Malaysian technicians stood by, listening with wide eyes. Zhong Renlong also did his best to translate, but facing a long string of professional terms and numbers, his voice became smaller and smaller.

"I'm done on my end." Liu Jinghui, whose eyes were red from drinking coffee, walked over.

"Can you identify the suspect?" Jiang Yuan dropped Wei Shiyan.

"As of now, there are 4 people who have no alibi. Or rather, their alibis are incomplete. Of course, I'm being quite strict." Liu Jinghui paused, then looked at Jiang Yuan and said: "These are all based on the time of death of the three victims, accurate to within 4 hours."

"Within 4 hours is no problem." Jiang Yuan nodded.

Jiang Yuan used the temporary +1 situation to provide a timeline of the time of death based on the temporary LV7 time of death judgment. Theoretically, this time interval could be further reduced, but if he were to judge the suspect based on this, Jiang Yuan still chose to be lenient toward the enemy.

Liu Jinghui nodded: "Although there are three murder cases, the killer's crime time was during rest periods. Two were during the day, and one was at night. For the case at night, there was very little room for screening. The remaining two daytime cases helped screen out most people."

Liu Jinghui then displayed the PPT of his and Wang Chuanxing's results on the projection screen.

After a gorgeous opening animation, each name was followed by their respective timelines.

In the three cases, focusing on the first two, the timeline for each person on that day, especially the total 4-hour timeline before and after the victim's death, was organized in great detail.

Liu Jinghui pointed with a laser pointer and said: "From the timeline, the killer upgraded their killing three times. For example, in the third case, the killer chose the killing time and location where surveillance could not play a role at all."

Liu Jinghui: "The 4 people I finally screened out are actually more than I expected. I originally thought that with 23 people, if we did a rough screening, even if we relaxed the screening conditions, if they could satisfy the crime time of all three cases, there might be only one or two people. I was even prepared for there to be no one. At that time, we would have to consider the possibility of an outsider committing the crime."

Liu Jinghui: "But from the results, actually half of the people, mainly technicians, spend most of their time working independently and are not under surveillance. For example, those who install shading nets, do mechanical repairs, and prune and plant—they not only work outside most of the time, but don't even go back for lunch, which gave the killer an opportunity."

Liu Jinghui: "In short, the final four people are production manager Li Wanzhong, and mechanical repairmen Zhang Fan and He Jun, and general worker He Cheng."

Following his words, Wang Chuanxing expanded the table for the four people.

Liu Jinghui coughed twice and said: "Among them, Li Wanzhong is the employee who has worked the longest in the rubber plantation and is also the oldest at present. As one of the people in charge of the rubber plantation, Li Wanzhong's daily workload is not low, and he has to spend most of his time in the office area. When the two murders occurred, Li Wanzhong had no alibi, which is also a suspicious factor..."

"Wait a minute!" Niza looked at his phone and suddenly interrupted Liu Jinghui.

Several people looked over.

Niza showed his phone screen: "Li Wanzhong committed suicide in his room."

(End of chapter)