Artificial color uses the projection of the spectrum into two or more broad, overlapping spectral bands to discriminate, pixel by pixel, among user-defined classes of objects. As initially practiced, it used a sequence of hyperspherical regions of the decision space to define class membership. Of course, a hypersphere is just a degenerate hyperellipsoid; thus, exploring the effect of loosening that degeneracy seemed appropriate. Initially, we use two-foci hyperellipsoids with a hyperellipsoidal distance metric to classify pixels with dramatic improvement in performance. We explore the work even further by allowing many foci and noting the effects of increased complexity of the decision surfaces. In the example case, three foci gave superior performance to one or two foci, but four added little improvement.
By definition, HSC (HyperSpectral Camera) images are much richer in spectral data than, say, a COTS (Commercial-Off-The-Shelf) color camera. But data are not information. If we do the task right, useful information can be derived from the data in HSC images. Nature faced essentially the identical problem. The incident light is so complex spectrally that measuring it with high resolution would provide far more data than animals can handle in real time. Nature's solution was to do irreversible POCS (Projections Onto Convex Sets) to achieve huge reductions in data with minimal reduction in information. Thus we can arrange for our manmade systems to do what nature did - project the HSC image onto two or more broad, overlapping curves. The task we have undertaken in the last few years is to develop this idea that we call Artificial Color. What we report here is the use of the measured HSC image data projected onto two or three convex, overlapping, broad curves in analogy with the sensitivity curves of human cone cells. Testing two quite different HSC images in that manner produced the desired result: good discrimination or segmentation that can be done very simply and hence are likely to be doable in real time with specialized computers. Using POCS on the HSC data to reduce the processing complexity produced excellent discrimination in those two cases. For technical reasons discussed here, the figures of merit for the kind of pattern recognition we use is incommensurate with the figures of merit of conventional pattern recognition. We used some force fitting to make a comparison nevertheless, because it shows what is also obvious qualitatively. In our tasks our method works better.
With the development of Charge Coupled Device (CCD) technology, the method to measure the optical system’s resolution with the machine sight has been applied widely, which can overcome the factor of subject error that will exist when adapting human being’s eyes to measure the resolution. With the radical target to measure the optical system’s resolution, it has many merits such as the measuring equipment is simple and the operation method is convenient. The measuring process is realized with a collimator and a CCD camera through adopting necessary image processing methods in the paper. The matching problem between the machine sight and the human being’s eyes when judging the optical system’s resolution is analysed firstly in the paper. And the critical contrast is got, which should be adopted when applying the machine sight to measuring the optical system’s resolution. Next step is to find where the resolution is nearest to the critical contrast in the target image. With the method present in the paper, we get it. So the resolution of the tested equipment can be figured out. Through contrastively analyzing the resolution data which is obtain with conventional method and with the method presented in the paper, it shows that the method to measuring the optical system’s resolution with radical target in the paper is viable completely.
Seeker is the key component in the laser guided weapons. Although the seeker has many anti-jamming measures such as the narrowband filter in the front of the seeker and the tracking gate processing circuit in signal processing part, and these anti-jamming measures are always effective for the low power jamming laser. As far as the high power laser which can pass though the filter is concerned, it is easy to make the detector saturate, which will lead the seeker into losing the capturing and tracking capability for the target. In the past ten years, the applied research of organic nonlinear materials which is according to the optical limiting effect has had great development in the laser technology field. And some of these materials have been put into practicability phase. This kind of materials is characterized by its wide absorption spectrum, obvious nonlinear effect and quick response speed, all of which excel the mineral. If this kind of materials can be applied into the laser seeker, it will remedy the laser seeker's defect that its protective capability is weak for the high power jamming laser. The whole applied scheme is present in this paper. And the anti-jamming capability of seeker is analysed constructively before and after the organic matter is applied in the laser seeker. The result indicates that this kind of method is viable in theory.
Position sensitive detector (PSD), which bases on the lateral photoelectric effect, is a novel position detector coming out in recent years. It can be applied to detect angle, height, distance and movement. In this paper, the development, principle, structure and its application in an active range finding system have been given.
A new type of design for the thermal imaging radiometer is presented in this paper. The new system has many advantages, such as that the apparent temperature configuration of the measured object is showed with image manner, that measure results and parameters of system status is displayed with graphics intuitively, that measure data can be saved easily and conducted further process, etc. Besides these, it has very nicer imaging radiation measure capability, high automatization degree. Its orientation is easy, and field experimental operation is convenient. With so many advantages, it offers an effective method to realize the spatial distributed measure for a target’s infrared radiation, the measure for its variation per hour and the measure for its intensity and dynamic range of the radiation.
In a Faraday optical-fiber current sensor, it has many kinds of linear double refraction inevitably because of the circular degree error of the optical fiber, deformation of pressure, temperature effect and other reasons. It results in an additional phase difference, which will affect the detecting sensitivity and even decrease it to zero. A new method that can eliminate the effect of linear double refraction is offered in this paper with phase conjugate device after analyzing the foundational operation principle of the Faraday optical-fiber current sensor and the effect of the linear double refraction.