Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Chapter 100 Mathematical Transformations
The investigation office of BZ City Criminal Investigation Detachment.

Wang Hao organized his own people to conduct DNA analysis on the physical evidence collected in the basement.

Lu Chuan also began to identify and analyze the thirteen fuzzy pockmarked face fingerprints.

In addition, some footprints were collected in the basement, and Lu Chuan also had to conduct identification and analysis.

"You will do this too?"

Wang Hao was a little surprised to see Lu Chuan processing the pictures of footprints. Footprint analysis is different from fingerprint identification.

Fingerprint identification and analysis, not to mention the criminal police who specialize in this bowl of food, even the general police at the police station, most of them can also participate.

But footprint analysis, compared with fingerprint identification, is much less popular.

Even Wang Hao himself can only figure out the height information of the footprint owner based on formulas such as seven times the length of the sole of the foot.

And this bit of information is obviously far from the real footprint analysis.

Lu Chuan took out a pack of soft Zhonghua, opened it, and handed one to Wang Hao: "I understand a little bit, I just heard that Chen Gang didn't explain anything, I think there should be a lot of traces left by him in the basement, and I'm not afraid to make it out." He won't give up."

Wang Hao took the Ruan Zhonghua handed over by Lu Chuan with some surprise, and understood in his heart.

My initial guess was correct. It seems that the Lu Chuanjin task force is not just because of good technology?

How many serious police officers are out there who smack China?

All fronts are at full strength!
Although Li Donglin has a technical background, he does have ideas in handling cases.

Currently, the three lines are advancing further.

On the one hand, it was mainly for Chen Gang's pre-examination. Since the hard ones are not good enough, they can only come over soft ones.

Chen Gang is from Haizhou City, and Qin Yong is already contacting his parents, trying to convert him with family affection.

The other party was done by Lu Chuan and the others, trying to obtain more evidence through technical means.

Another aspect is the biotechnology companies that give 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, who are tracking down the other party's information, but there is no progress yet.

The other parties registered short companies, and the actual address did not have this Wang Liang.

Lu Chuan, who has mastered advanced fingerprint identification and analysis skills, has also greatly improved his speed when processing footprint pictures.

After data measurement and calculation, compared with Chen Gang's footprint samples, the same identification was quickly made.

The footprint identification this time was somewhat different from what Lu Chuan had done in the past.

In the past, it was more difficult to analyze the owner's physical signs through the footprints at the scene of the crime.

But this time, it is only necessary to prove that the footprints in the basement are those of Chen Gang.

This is much easier.

The next step was the highlight, the identification and analysis of the thirteen fingerprints.

This time, Lu Chuan did not directly use the image processing software that comes with the fingerprint comparison system to preprocess the fingerprints.

Instead, professional PS image processing software was used.

Blurred fingerprints, with several layers stacked together, require layering of the fingerprint image.

The image processing software that comes with the system cannot handle this function.

There is also the processing of clarity, which can be said to be the most important ability in Lu Chuan's advanced fingerprint identification analysis.

The sharpness processing of fingerprints is simpler than the general photo sharpness processing.

After all, fingerprint pictures are just complex, interlaced, crushed lines.

Unlike normal images, color transformations are involved.

But even so, it's not an easy job.

To sort out a messy fingerprint image into a clearer image that can be identified and analyzed 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 a computer is actually a binary "0" and "1" relationship.

The fingerprint image that Lu Chuan saw on the computer screen is essentially a transformation of numbers.

Fingers interlaced, Lu Chuan first transformed the graphics.

Here, he uses 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 transformation domain image with functions and matrices. Such operations are more conducive to feature extraction, enhancement, compression, and image coding of images.

Then, Lu Chuan used Fourier transform to analyze the characteristics of the two-dimensional spectrum of the original image.

This alone is not enough, Lu Chuan will use the Walsh-Hadama transform next, which is a kind of operation of adding and subtracting the two-bit spectrum of the image, which can complete the transformation of the image on the basis of the Fourier transform. Second edit.

The last is the discrete Kavner-Levy transform, which is the final method of image filtering, compression, and clarity purification.

Of course, among the skills obtained by Lu Chuan, there are also cosine transform, sine transform, Haar transform and oblique transform, etc., but the processing methods chosen to deal with fingerprints of different degrees are also different.

The fingerprint we are dealing with now works best with Fourier Transform, Walsh-Hadama Transform and Discrete Kavner-Levy Transform in the experience of advanced fingerprint identification analysis skills.

Focused men are most likely to be favored by the opposite sex, which seems to be a motto everywhere.

Hu Xiaoyue, a college student who only came in last year from the current survey office of the Criminal Investigation Detachment of BZ City, is still in the stage of doing odd jobs.

Just as Wang Hao ordered, he came over to pour tea for Lu Chuan, and saw magically changing images and piles of data streams on the computer screen.

This is not engaging in fingerprint identification and analysis, the entire Matrix.

In addition, Lu Chuan's sharp-edged profile, under the flickering blue light of the computer screen, has a magical color.

As a result, a strange scene unfolded, Lu Chuan stared at the computer screen, his hands waving rapidly on the keyboard.

Behind him, a tall policewoman in police uniform was holding a teacup, staring at Lu Chuan in front of the computer for a moment.

Forensic Shen obviously couldn't see this scene.

Thirteen fingerprints, the processing speed is not slow.

With the blessing of advanced fingerprint identification and analysis skills, Lu Chuan can process a fingerprint in about 10 minutes.

Hu Xiaoyue was surprised that she witnessed how a paste-like fingerprint turned into a normal fingerprint.

It's as if this fingerprint went to Bangzi Country and had the most delicate plastic surgery.

Although the face is still the same face, but it is not all the same face.

The eyes are bigger, the nose is straighter, and the lips are fuller.

Every detail exudes comfort.

The fingerprint comparison system of the Criminal Investigation Detachment of Binhai City is the same as that of Haizhou City, and Lu Chuan's account can still be logged in here.

After one fingerprint was processed, the thirteen special points were marked immediately.

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 match mode.

After processing the system data, Lu Chuan minimized the interface, and dragged the second fingerprint image to the image processing interface of PS software.

Once again, the transformation of the number of figures, the transformation of the number of figures begins again.

(End of this chapter)