59 results about "Pattern frequency" patented technology

A method of detecting malicious binary executable files is accomplished by inputting a binary executable file; converting the binary executable file to byte hexadecimal text strings; calculating the frequency of each byte pattern in the byte hexadecimal text strings; selecting characteristic byte pattern frequencies as discriminating features; classifying the discriminating features as malicious or benign; labeling the binary executable file as malicious or benign; and outputting the labeled malicious or benign binary executable file.

Threshold matrixes for a C-separation and an M-separation of main colors are used to convert a continuous-tone image subjected to color separation into dot patterns for the C-separation and the M-separation. The dot patterns are binary images in which no screen ruling or screen angle is defined. Then, a color image is reproduced by overlaying the dot patterns for the C-separation and the M-separation. When the dot patterns for the C-separation and the M-separation are converted into patterns in the frequency domain, main frequency components obtained by the conversion have a substantially-constant predetermined pattern frequency for all angles, and the intensity distribution of the main frequency components is varied based on the C-separation and the M-separation.

Frequency varying patterns are aligned on the front and back surfaces of a document to provide an anti-counterfeiting security device. The frequency varying patterns are reversed images. The document is sufficiently transparent to allow see-through of the pattern on the back of the document to be superimposed on the pattern on the front of the document. The frequency varying patterns will form a moire pattern if misaligned, regardless of the magnitude and the orientation of the misalignment.

A method for training a pattern recognition algorithm including the steps of identifying the known location of the pattern that includes repeating elements within a fine resolution image, using the fine resolution image to train a model associated with the fine image, using the model to examine the fine image resolution image to generate a score space, examining the score space to identify a repeating pattern frequency, using a coarse image that is coarser than the finest image resolution image to train a model associated with the coarse image, using the model associated with the coarse image to examine the coarse image thereby generating a location error, comparing the location error to the repeating pattern frequency and determining if the coarse image resolution is suitable for locating the pattern within a fraction of one pitch of the repeating elements.

A tunable lasing device (100) comprising a ring-shaped laser cavity (102), an optical gain element (104), a bi-directional output coupler (106) and a frequency selection means (114). The frequency selection means is generally a grating with a refractive index that determines a grating reflection frequency. Single mode laser operation is achieved where a cavity mode frequency of the ring-shaped laser cavity coincides with a grating reflection frequency. The refractive index of the grating can be modified by the injection of a variable current. In this way, the lasing frequency can be rapidly tuned between cavity mode frequencies.

The invention relates to a device and a method for measuring visual threshold values, and belongs to the technical field of optical precision measurement. The device for measuring the visual threshold value comprises a first uniform surface light source, a second uniform surface light source, a first fundamental color matching system, a second fundamental color matching system, a first complementary color matching system, a second complementary color matching system, a first color mixing system, a second color mixing system and a beam splitting system. A set of multi-parameter measurement device for the visual threshold values is implemented by utilizing a four-integrating sphere light source system and multiplexing the color matching systems, the color mixing systems and a subsequent light path to generate four observation targets of which the brightness (illuminance), the contrast, the chromaticity and the periodic pattern frequency are variable, and can be used for simultaneously measuring visual illuminance, contrast and chromatic aberration threshold values, so that the device is convenient to operate, wide in measurement range and color gamut adjustment range and higher in light source output power, and a plurality of parameters can be measured.

A normalization threshold side size Nr which serves as an index indicative of how many times the pattern frequency r is repeated in one threshold matrix is defined as Nr=N×r / R where N represents a size of one side of the threshold matrix as the number of pixels, and the threshold array of the threshold matrix is determined such that the normalization threshold side size Nr is of an value greater than 65.

An external cavity laser includes a lasing cavity and an optically coupled feedback cavity having differently spaced resonant lasing and feedback mode frequencies. The lasing modes can be collectively or individually matched to selected feedback modes. For example, a current driving the lasing cavity can be adjusted to shift individual lasing modes into alignment with the selected feedback modes.