BZ City Criminal Investigation Detachment’s current investigation office.
Wang Hao organized his own people to begin DNA identification and analysis of the evidence collected in the basement.
Lu Chuan also began to conduct identification and analysis on the thirteen pockmarked face fingerprints that were blurred into paste.
In addition, some footprints were also collected in the basement, and Lu Chuan also wanted to conduct identification and analysis.
"You know this too?"
Wang Hao was a little surprised to see Lu Chuan processing the footprint pictures. Footprint analysis is different from fingerprint identification.
Fingerprint identification and analysis, not to mention the criminal policemen who specialize in this bowl of rice, even ordinary policemen at the police station, most of them can also participate.
However, compared to fingerprint identification, footprint analysis is much less popular.
Even Wang Hao himself could only derive the height information of the footprint owner based on a formula such as seven times the length of the sole of the foot.
And this bit of information is obviously far from true footprint analysis.
Lu Chuan took out a pack of soft Chinese medicine, opened it, and handed one to Wang Hao: "Know a little bit, I just heard that Chen Gang didn't confess anything. I thought there should be a lot of traces left by him in the basement, and I'm not afraid of doing it. He doesn’t give up.”
Wang Hao took the soft Chinese handed over by Lu Chuan with some surprise, understanding in his heart.
My initial guess was right. It seems that this Lu Chuanjin task force is not just because of his good skills?
How many serious police officers are there to crack down on Chinese people?
All fronts are at full strength!
Although Li Donglin comes from a technical background, he does have ideas for handling cases.
At present, three lines are further advanced.
On the one hand, it is mainly for Chen Gang's pre-trial. Since it is too hard, it can only be soft.
Chen Gang is from Haizhou City, and Qin Yong is already contacting his parents, trying to empathize with him with family.
On the other side, Lu Chuan and the others are trying to get more evidence through technical means.
On the other hand, there are biotechnology companies that provide money to Wang Manli. The owners or major shareholders of these companies are all named Wang Liang.
There are economic investigation experts in the task force, and they are tracking down the other party's information, but there is no progress yet.
The other party registered short-selling companies, and Wang Liang did not exist at the actual address.
Lu Chuan, who has mastered advanced fingerprint identification and analysis skills, has greatly improved his speed when processing footprint images.
After measuring, calculating and comparing the data with Chen Gang's footprint samples, the same identification was quickly made.
This time's footprint identification was a little different from what Lu Chuan had done before.
In the past, it was more difficult to analyze the owner's physical signs through the footprints at the crime scene.
But this time we only need to prove that the footprints in the basement are Chen Gang's.
This is much simpler.
Next is the highlight, the identification and analysis of thirteen fingerprints that were lumped into a ball.
This time, Lu Chuan did not directly use the image processing software that comes with the fingerprint comparison system to preprocess the fingerprints.
Instead, I used professional PS image processing software.
Blurred fingerprints have several layers superimposed on each other, and the fingerprint image needs to be processed in layers.
The image processing software that comes with the system is not capable of this function.
There is also clarity processing, which can be said to be the most important ability in Lu Chuan's advanced fingerprint identification analysis.
Fingerprint clarity processing is simpler than general photo clarity processing.
After all, fingerprint images are just complex, intertwined, and crushed together lines.
Unlike ordinary images, which involve color transformation.
But even so, it's not an easy job.
To sort out a messy fingerprint image into a clearer image that can be used for identification and analysis requires superb mathematical knowledge and image processing knowledge.
As for why mathematical knowledge is used, it has something to do with the principles of computers.
Any data stored in the computer is actually a binary "0" and "1" relationship.
The fingerprint image Lu Chuan saw on the computer screen was essentially a transformation of numbers.
Interlacing his fingers, Lu Chuan first transformed the graphics.
Here, he used orthogonal functions and orthogonal matrices to perform a two-dimensional linear reversible transformation on the original image.
Professionally speaking, it is to transform the original image, that is, the spatial domain image, into a transformed domain image using functions and matrices. This operation is more conducive to feature extraction, enhancement, compression and image coding of the image.
Lu Chuan then used Fourier transform to perform feature analysis on the two-dimensional spectrum of the original image.
This alone is not enough. Lu Chuan will also use the Walsh-Hadamard transform, which is an operation of adding and subtracting the two-bit spectrum of the image. It can complete the image transformation based on the Fourier transform. Second edit.
The last is the discrete Cavner-Levy transform, which is the final method of image filtering, compression, and definition purification.
Of course, among the skills Lu Chuan obtained, there are also cosine transformation, sine transformation, Haar transformation, oblique transformation, etc. However, the processing methods chosen to deal with fingerprints with different degrees of badness are also different.
For the fingerprint being processed now, in the experience of advanced fingerprint identification analysis skills, Fourier transform, Walsh-Hadamard transform and discrete Cavner-Levy transform work best.
A man who is dedicated is the easiest to win the favor of the opposite sex. This seems to be a motto everywhere.
Hu Xiaoyue, a college student who only joined the current investigation office of the BZ City Criminal Investigation Detachment last year, is still doing odd jobs.
Just as he came over to pour tea for Lu Chuan according to Wang Hao's instructions, he saw magically changing images and piles of data flowing on the computer screen.
This isn't about fingerprint identification and analysis, it's a whole Matrix.
In addition, Lu Chuan's angular profile looked quite magical under the flickering blue light of the computer screen.
As a result, a strange scene unfolded. Lu Chuan stared at the computer screen and moved his hands quickly on the keyboard.
Behind him, a tall policewoman in police uniform was holding a teacup and staring at Lu Chuan in front of the computer.
Forensic Doctor Shen obviously couldn't see this scene.
Thirteen fingerprints, the processing speed is not slow.
With the help of advanced fingerprint identification and analysis skills, it took Lu Chuan about twenty minutes to process a fingerprint.
Hu Xiaoyue was surprised to witness with her own eyes how a pasty fingerprint turned into a normal fingerprint.
It's as if this fingerprint went to Bangzi Country and underwent the most elaborate plastic surgery.
Although the face is still the same face, it is not entirely the same face.
The eyes are bigger, the nose is straighter, and the lips are plumper.
Every detail exudes comfort.
The fingerprint comparison system of the Binhai City Criminal Investigation Detachment is the same as the fingerprint comparison system of Haizhou City, and Lu Chuan's account can still be logged in here.
After one fingerprint is processed, the thirteen special points are immediately marked.
A string of data is generated under the fingerprint, and the coordinate data of each feature point begins to enter the system.
Lu Chuan still chose the exact matching mode.
After processing the system data, Lu Chuan minimized the interface and dragged the second fingerprint image into the image processing interface of the PS software.
Once again, the picture-to-number transformation begins again.
