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

Chapter 66 The match was successful
In fingerprint identification analysis, collecting fingerprints is only the first step.

It is the basis for all subsequent work.

Just like building a building, if the foundation is not in place, the building cannot be built high.

It’s also like going to some KTVs with diversified services to sing. There is a gap between the 800 yuan service and the 1000 yuan singing lady.

It's not that the more money you have, the less you wear. On the contrary, the more money you have, the more clothes you may wear.

Lu Chuan's basic work is completed, and the rest will enter the topic.

With intermediate fingerprint collection skills, Lu Chuan can handle most of the fingerprint collection needs.

Next, it is time for intermediate fingerprint identification and analysis skills to show their talents.

Although he stayed up all night and was physically exhausted, Lu Chuan was in a relatively excited state.

Although the process of collecting fingerprints is very complicated and boring.

But the more difficult the fingerprint collection, the greater the sense of accomplishment after success.

In front of the computer, Lu Chuan stared at the screen with red eyes.

Lu Chuan still uses the image processing software that comes with the fingerprint comparison system.

The first thing he got was the fingerprints collected from the frame of the painting that Yang Sen and Lao Bai failed to compare yesterday.

Compared with the two or three hours that Laobai and Bai could process a fingerprint, Lu Chuan's processing speed was much faster.

Enlarged fingerprints, like line drawings, have curved and twisted lines and are distributed irregularly on the screen.

The pretreatment that Lu Chuan needs to do now is to restore the fingerprints that have been severely deformed due to force and friction to their normal form.

And look for feature comparison points based on experience.

At this moment, Liu Guodong, Yang Sen and Lao Bai were all watching quietly behind Lu Chuan.

"Last time, I remember Xiao Lu said that he has research on fingerprint collection, but he is not good at fingerprint identification..."

But Lao Bai looked at the speed at which Lu Chuan's operating software processed fingerprint images, and it was obviously not normal.

Liu Guodong also frowned as he watched Lu Chuan preprocess the fingerprints.

Among the three, his level is the highest, and Lu Chuan has been studying with him since he went to work.

Including the previous few fingerprint identifications, Liu Guodong also told Lu Chuan some techniques and methods.

Therefore, Liu Guodong knew about Lu Chuan's fingerprint identification level.

I have mastered some skills and have relatively solid theoretical knowledge, but lack experience and exercise.

But in the past few days, Liu Guodong actually had a feeling that he couldn't understand Lu Chuan's operations on the computer.

A fingerprint photo is constantly zooming in and out, feature points are marked one by one, then canceled and marked again.

Liu Guodong felt a little dazzled when he saw it.

call!
Heaving a sigh of relief, Lu Chuan finally got a fingerprint. The intermediate fingerprint identification and analysis skills brought him not only many skills that he had never touched before.

There is also a wealth of experience, and the direct benefit is that the speed of identification and analysis is greatly improved.

"Put it in the system and run aside first."

Lu Chuan talked to himself, and directly entered the fingerprints that had just been processed into the fingerprint comparison system.

Stretching, Lu Chuan got up and almost fell down in fright.

"Master, why are you here?"

Facing the three big heads, Lu Chuan looked confused.

cough cough.

Liu Guodong coughed twice: "I saw you processing fingerprints just now, let's come over and take a look."

"Yes, come and have a look."

"We just came here too."

Yang Sen and Lao Bai cooperated with Liu Guodong in very standard postures.

"Xiao Lu, what you just dealt with were the fingerprints taken from yesterday's frame, right?"

Lao Bai was very impressed with the few fingerprints yesterday, and stared at them for two or three hours, so he recognized at a glance that Lu Chuan was dealing with the fingerprint he fought yesterday.

However, the result is obviously because Lao Bai's technology is not good enough, and the fingerprints he got are not satisfactory, which is not good at all.

Lu Chuan nodded and rubbed his eyes: "This fingerprint is seriously deformed and has some scratches, but fortunately there are not many breakpoints, and it is relatively simple and easy to handle."

Simple?
Easy to do?

Lao Bai swallowed, he didn't think this fingerprint was easy and easy to get yesterday.

The preprocessing of deformed fingerprints has always been a difficult problem.

It is a hurdle to test the strength of the trace inspection criminal police.

Lao Bai and Yang Sen are at the bottom of the criminal police food chain.

Much better than Mengxin college students, with rich experience and many native methods.

Some fingerprints with less severe deformation can be compared successfully.

Far stronger than the technicians of the county-level criminal police brigade.

In the eyes of the people below, Lao Bai and Yang Sen are already the technical powers that normal criminal police can come into contact with, at the ceiling level.

However, there is nothing we can do about the scratched and severely deformed fingerprints extracted from yesterday's picture frame.

Just like chasing women, the levels that Lao Bai and Yang Sen can handle are limited.

Liu Guodong's strength is stronger.

In dealing with some complex fingerprint identification, such as fingerprints with serious deformation, the probability of successful comparison is much higher than that of Lao Bai and Yang Sen.

Among the dozen or so criminal investigation detachments in the province, they belonged to the level of normal technical leaders.

It can meet the needs of on-the-spot investigation and trace inspection of generally less complicated major cases.

But compared with the experts from the provincial department, there is still a lot of gap.

Just met the requirements for participating in the fingerprint battle at the provincial level, the bottom one.

But now, Lu Chuan was doing fingerprint identification and analysis, which made Liu Guodong feel like watching senior experts from the provincial department do fingerprint identification.

Know what you're doing, but don't quite know it.

It's like... it went in, but it didn't seem to be long enough, and it didn't go in completely.

If you describe it in one sentence, it would be unclear.

Ding!
Just as he was thinking, a characteristic beep sounded from the computer speaker.

The three of Liu Guodong, who basically deal with the fingerprint comparison system every day, are all too familiar with this voice.

"Success?"

A surprised expression flashed across Lao Bai's face, and he jumped on the screen.

"The comparison was successful!"

The fingerprint comparison system used by the Haizhou Criminal Investigation Detachment was built from the first generation system.

Basically, system upgrades are performed every year.

So far, there are basically three modes for the system to compare fingerprints.

First, the comparison fails.

Commonly known as fool mode.

After the fingerprints are preprocessed, the system will compare the features of all the fingerprints in the database according to the feature points marked in advance.

This has relatively low requirements for fingerprint identification.

Because only one feature point needs to be determined, as long as this feature point is different from the same feature point of other fingerprints, the judgment can fail.

The comparison is complete.

However, there is a problem with such a comparison, that is, when preprocessing the fingerprints, the selection of feature points must be standard.

Only by selecting a standard can the comparison be successful.

If the selected position is not standard, it will definitely fail.

This is why the comparison between Lao Bai and Yang Sen failed last night.

When they preprocessed the fingerprints, they were unsuccessful, and there was a problem with the selected feature points.

The second mode is similarity comparison.

This is also the most commonly used identification analysis method. The system will fully match the fingerprints in the database according to the feature points marked by the fingerprints.

Then according to the similarity of the feature points, a ranking is given.

Of course, this does not mean that the first place must be the successful comparison object.

It is also necessary to manually confirm the two fingerprints. If obviously different feature points can be found, the comparison will fail.

The advantage of this mode is that the system will give dozens or even hundreds of similar fingerprints.

It is very likely that there is a target fingerprint here, but it needs to be checked manually.

The last one is the fingerprint comparison method chosen by Lu Chuan.

(End of this chapter)