Abstract: In one implementation, a method of compressing an image is performed at a device including one or more processors and non-transitory memory. The method includes obtaining an uncompressed image. The method includes compressing the uncompressed image to generate a compressed image by mapping a substantially circular portion of the uncompressed image to a substantially square portion of the compressed image, wherein a central region of the substantially circular portion of the uncompressed image is compressed more than a remainder of the substantially circular portion of the uncompressed image.

Abstract: Encoding an image stream may include receiving an image stream with an original image resolution; generating a plurality of copies of the image stream with the original image resolution; encoding, for each copy of the plurality of copies of the image stream, the copy of the image stream to generate an encoded copy of the image stream, wherein the encoded copy of the image stream comprises a first region having a first image resolution and a second region having a second image resolution, wherein each encoded copy of the plurality of encoded copies of the image stream has a different first region, and providing, to a playback device, at least one encoded copy of the plurality of encoded copies of the image stream.

Abstract: A Schlieren imaging system can comprise a digital display configured to provide a background for Schlieren imaging, a cutoff filter onto which the background is focused, and a camera configured to image the cutoff filter and the background to facilitate Schlieren imaging. A calibration method for the Schlieren imaging system can comprise forming a pixel image on a digital display, focusing the pixel image on the cutoff filter, imaging the cutoff filter and the pixel image with a camera; and moving the pixel image with respect to the cutoff filter to align the pixel image with respect to the cutoff filter to facilitate Schlieren imaging. Thus, alignment of the Schlieren imaging system can be substantially simplified.

Abstract: A Schlieren imaging system can comprise a digital display configured to provide a background for Schlieren imaging, a cutoff filter onto which the background is focused, and a camera configured to image the cutoff filter and the background to facilitate Schlieren imaging. A calibration method for the Schlieren imaging system can comprise forming a pixel image on a digital display, focusing the pixel image on the cutoff filter, imaging the cutoff filter and the pixel image with a camera; and moving the pixel image with respect to the cutoff filter to align the pixel image with respect to the cutoff filter to facilitate Schlieren imaging. Thus, alignment of the Schlieren imaging system can be substantially simplified.

Abstract: A system for quantifying surface characteristics detects and quantifies characteristics of a surface of an object. For example, the system may quantify changes in surface roughness without contacting the specimen and without requiring precise temporal or spatial stability. The system may also quantify the evolution or progression of a particular characteristic of a surface, such as a defect, a slipband, a crack, a microcrack, a pit, a damage feature, corrosion, a contour change, an impact crater, a change in residual stress, and so on. The system may include an energy source, a detector section, and a process section. The energy source transmits a source signal to the surface of the object. The source signal is specularly reflected and/or scattered by the surface to yield one or more received signals. The detector section receives the received signal and, in turn, provides a detector signal indicative of the received signal.