Abstract: A method of multi-resolution adaptive correlation processing of images, such as seeded fluid flow images, to efficiently increase the spatial resolution and dynamic range of detecting particle image displacements in the images. The technique takes full advantage of the multi-resolution characteristic of the discrete correlation function by starting the processing at the smallest scale and if necessary gradually building correlation planes into larger interrogation areas based on the result of inter-level correlation correction and validation. It is shown that the method can be implemented in both direct and FFT based correlation algorithms with greatly reduced computational complexity. Processing the images at the lowest scale (e.g. pixel or particle image size) allows the combination of correlation planes of various shapes both in space and in time for maximizing the correlation plane signal-to-noise ratio or for estimating statistical flow parameters.

Abstract: The invention relates to new compounds of the general formula (I), ##STR1## wherein R.sup.1 is hydrogen or a lower alkoxy group andZ.sup.1 is hydrogen, orR.sup.1 and Z.sup.1 form together a double bond,Z.sup.2 is hydrogen andB is hydroxy, orZ.sup.2 and B form together a double bond,Z.sup.3 and Z.sup.4 each stand for hydrogen or they form together an ethylene group, orZ.sup.4 and D form together a double bond,C is oxygen atom or a lower alkoxy group,D is a valence bond if C stands for oxygen, or otherwise D forms a double bond together with Z.sup.4 or Z.sup.5,Z.sup.5 forms a double bond together with D or represents hydrogen, andR.sup.2 is a group of the general formula --COOR.sup.3, wherein R.sup.3 is lower alkyl, orZ.sup.5 and R.sup.2 form together a 1-oxo-2-oxa-tetramethylene group, with the proviso that if Z.sup.3 and Z.sup.4 form together an ethylene group, R.sup.2 may stand only for a --COOR.sup.3 group,insecticidal compositions containing them, as well as to a process for their preparation.