Abstract:
A method for a copy-paste tampered image detection, including: extracting, using a scale-invariant feature transformation algorithm, key points of an image and features corresponding to the key points; constructing, using a gradient hash matching algorithm, a hash table based on the features, and putting the key points into rows corresponding to serial numbers of the hash table; performing a matching operation, using a k-nearest neighbor algorithm, on the key points in each row of the hash table to obtain key point pairs; and clustering and grouping, using a distance clustering filtering algorithm, the key point pairs, and retaining the key point pairs in a cluster group whose number of the key point pairs is greater than a quantity threshold; and marking circles in the image with each key point, in the key point pairs that are retained, as a center and according to a specified radius.
Abstract:
The present disclosure relates to a method and system for multi-source algae image target detection, and relates to the field of monitoring of algal bloom events in fresh water. The method includes first crawling images of algae of a selected species by using a built automated algae crawling tool, where the images include all formats; classifying and labeling algae in the algae images, and forming a source domain dataset by using all the classified and labeled algae images; performing transfer learning by using a faster recurrent revolutional neural network (Faster RCNN) with reference to a target domain dataset, to obtain a multi-source algae image target detection model; and finally performing identification and classification by using the multi-source algae image target detection model.
Abstract:
An optical fiber environmental detection system comprising an interferometer, a broadband light source and a detector is disclosed. The interferometer further comprises a thin core fiber, a first single mode fiber and a second single mode fiber; wherein the thin core fiber is coupled to the first and second single mode fiber via a first junction and a second junction respectively. When an emission light reaches the first junction, high-order cladding modes will be excited. The excited cladding modes will interfere with the core mode at the second junction. The interferences determine the intensity maximum or minimum of the received signal. When there is an ambient environmental change, a shift of the received signal would be induced. According to the shift, environmental change, for instance ambient temperature, could be determined.
Abstract:
A method of generating Raman laser for inducing fluorescence of pyrene and a system thereof is disclosed. The system comprises a pulsed laser, a frequency doubling crystal, a frequency quadrupling crystal, a light filter unit, a Raman cell, a prism, an optical diaphragm, an object lens and an optical fiber. The method of the present invention comprises the steps of emitting a laser beam pulse through the crystals as mentioned above such that a mixture of lasers of different wavelength is generated. The light filter unit is used to obtain a pure pump laser from the mixture of lasers. Finally, the Raman laser is obtained by directing the pump laser into a Raman cell, extracting different orders of stimulated Raman scattering lasers emitted from the Raman cell by the prism and selecting a predetermined order of stimulated Raman scattering laser by the optical diaphragm.
Abstract:
An optical detection system for measuring a refractive index of a liquid analyte comprising a light transmitting assembly fiber, which includes a single-mode fiber, an optical fiber sensing module and a multi-mode fiber. The optical detection system is configured to emit a coherent light beam to one end of the assembly fiber; and a detector is configured to capture a specklegram from an exit end of the assembly fiber. When the optical detection system is in operation, the optical fiber sensing module is configured to be submerged into the liquid analyte. By analyzing the correlation between the specklegram corresponding to the liquid analyte and the reference specklegram, the refractive index of the liquid analyte can be obtained.
Abstract:
A vibration detection system comprises a light source, a biconical tapered fiber comprising a biconical fiber taper and a detector is disclosed. The emission light emitted by the light source is directed to the biconical tapered fiber in one side. A detector is coupled to the other end of the biconical tapered fiber to measure the intensity of the light passing through. When the biconical tapered fiber is exposed to an external vibration, the biconical fiber taper deforms and modulates the light intensity accordingly. The received signal is then fed to the microcomputer to determine the amplitude and frequency of the external vibration. A method of vibration detection is also disclosed.