3 research outputs found
METHOD FOR ASSESSING THE SYMMETRY OF OBJECTS ON DIGITAL BINARY IMAGES BASED ON FOURIER DESCRIPTOR
In this paper we solve the problem of finding the symmetry axis of the object in a digital binary image. A new axial symmetry criterion is formulated for a connected discrete object. The problem of determining the symmetry measure and finding the symmetry axes arises in a variety of applications. In discrete images, exact symmetry is possible only in special cases. The disadvantage of the existing methods solving this problem is the high computational complexity. To improve computational efficiency, it is proposed to use the so-called Fourier descriptor. A new method for estimating the asymmetry of a discrete silhouette is proposed. The described algorithm for calculating the measure of asymmetry and determining the axis of symmetry is quadratic by the number of contour points. Methods for reducing the volume of calculations using a convex hull and taking into account the values of the modules of Fourier coefficients are proposed. Computational experiments are conducted with silhouettes of aircraft extracted from earth remote sensing images. The reliability of the described solution is established
ΠΠ°ΡΠ°Π»Π»Π΅Π»ΡΠ½ΡΠ΅ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ² Π½Π°Ρ ΠΎΠΆΠ΄Π΅Π½ΠΈΡ Π·Π΅ΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ Π±ΠΈΠ½Π°ΡΠ½ΡΡ ΡΠ°ΡΡΡΠΎΠ²ΡΡ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ
ΠΡΠ΅Π½ΠΊΠ° ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΡΠ½ΠΎΡΡΠΈ ΡΠΈΠ³ΡΡ ΡΠ²Π»ΡΠ΅ΡΡΡ Π²Π°ΠΆΠ½ΡΠΌ ΡΡΠ°ΠΏΠΎΠΌ Π°Π½Π°Π»ΠΈΠ·Π° Π±ΠΈΠ½Π°ΡΠ½ΡΡ
ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ ΠΈ ΠΌΠΎΠΆΠ΅Ρ ΠΏΡΠΈΠΌΠ΅Π½ΡΡΡΡΡ Π΄Π»Ρ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΠΌΠ½ΠΎΠ³ΠΈΡ
ΠΏΡΠΈΠΊΠ»Π°Π΄Π½ΡΡ
Π·Π°Π΄Π°Ρ ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΠΎΠ³ΠΎ Π·ΡΠ΅Π½ΠΈΡ, ΡΠ°ΠΊΠΈΡ
, Π½Π°ΠΏΡΠΈΠΌΠ΅Ρ, ΠΊΠ°ΠΊ Π°Π½Π°Π»ΠΈΠ· ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΠΏΡΠΎΠΈΠ·ΡΠ°ΡΡΠ°Π½ΠΈΡ ΡΠ°ΡΡΠ΅Π½ΠΈΠΉ, Π±ΠΈΠ»Π°ΡΠ΅ΡΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ Π½Π°ΡΠ΅ΠΊΠΎΠΌΡΡ
. ΠΠ·Π²Π΅ΡΡΠ½ΡΠ΅ Π°Π»Π³ΠΎΡΠΈΡΠΌΡ ΠΏΠΎΠΈΡΠΊΠ° ΠΎΡΠΈ Π·Π΅ΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡ Π½Π°ΠΉΡΠΈ Π»ΠΈΡΡ ΠΏΡΠΈΠ±Π»ΠΈΠΆΠ΅Π½Π½ΠΎΠ΅ ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ Π΄Π°Π½Π½ΠΎΠΉ Π·Π°Π΄Π°ΡΠΈ, ΠΊΠ°ΠΊ ΠΏΡΠ°Π²ΠΈΠ»ΠΎ, Π½Π΅ ΠΏΡΠ΅Π΄ΠΎΡΡΠ°Π²Π»ΡΡ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΠΎΡΠ΅Π½ΠΈΡΡ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΠΎΠ³ΠΎ ΡΠ΅ΡΠ΅Π½ΠΈΡ. ΠΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΡΠΌ ΡΠΏΠΎΡΠΎΠ±ΠΎΠΌ ΠΎΡΠ΅Π½ΠΊΠΈ ΠΊΠ°ΡΠ΅ΡΡΠ²Π° Π² Π΄Π°Π½Π½ΠΎΠΌ ΡΠ»ΡΡΠ°Π΅ ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ Ρ ΡΠΎΡΠ½ΡΠΌ ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ΠΌ - ΡΡΠ°Π»ΠΎΠ½Π½ΠΎΠΉ ΠΎΡΡΡ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ, ΠΌΠ΅ΡΠ° ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΡΠ½ΠΎΡΡΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ ΠΎΡΠ½ΠΎΡΠΈΡΠ΅Π»ΡΠ½ΠΎ ΠΊΠΎΡΠΎΡΠΎΠΉ ΠΈΠΌΠ΅Π΅Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅. Π Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΡΡΡ ΡΠΎΡΠ½ΡΠΉ ΠΌΠ΅ΡΠΎΠ΄ ΠΏΠΎΠΈΡΠΊΠ° ΡΠ°ΠΊΠΎΠΉ ΡΡΠ°Π»ΠΎΠ½Π½ΠΎΠΉ ΠΎΡΠΈ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ, ΠΎΡΠ½ΠΎΠ²Π°Π½Π½ΡΠΉ Π½Π° ΠΏΠΎΠ»Π½ΠΎΠΌ ΠΏΠ΅ΡΠ΅Π±ΠΎΡΠ΅ Π²ΡΠ΅Ρ
ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΡΠ½ΠΎ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΡΡ
ΠΎΡΠ΅ΠΉ ΠΈ ΠΎΡΠ΅Π½ΠΊΠ΅ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΡΠ½ΠΎΡΡΠΈ ΡΠΈΠ³ΡΡΡ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΠ΅ΠΎΡΠ΅ΡΠΈΠΊΠΎ-ΠΌΠ½ΠΎΠΆΠ΅ΡΡΠ²Π΅Π½Π½ΠΎΠ³ΠΎ ΠΏΠΎΠ΄ΠΎΠ±ΠΈΡ ΠΠ°ΠΊΠΊΠ°ΡΠ΄Π°, ΠΏΡΠΈΠΌΠ΅Π½ΡΠ΅ΠΌΠΎΠ³ΠΎ ΠΊ ΠΏΠΎΠ΄ΠΌΠ½ΠΎΠΆΠ΅ΡΡΠ²Π°ΠΌ ΠΏΠΈΠΊΡΠ΅Π»Π΅ΠΉ ΡΠΈΠ³ΡΡΡ ΠΏΡΠΈ Π΄Π΅Π»Π΅Π½ΠΈΠΈ Π΅Π΅ ΠΎΡΡΡ. ΠΠ»Π³ΠΎΡΠΈΡΠΌ ΠΏΠΎΠ»Π½ΠΎΠ³ΠΎ ΠΏΠ΅ΡΠ΅Π±ΠΎΡΠ° Π³Π°ΡΠ°Π½ΡΠΈΡΠΎΠ²Π°Π½Π½ΠΎ Π½Π°Ρ
ΠΎΠ΄ΠΈΡ ΡΡΠ°Π»ΠΎΠ½Π½ΡΡ ΠΎΡΡ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ, Π½ΠΎ ΡΡΠ΅Π±ΡΠ΅Ρ Π²Π΅ΡΡΠΌΠ° Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ Π½Π° ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΡ ΠΊΠ°ΠΆΠ΄ΠΎΠ³ΠΎ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ. ΠΠ»Ρ Π΄ΠΎΡΡΠΈΠΆΠ΅Π½ΠΈΡ ΡΠΊΠΎΡΠΎΡΡΠΈ, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠ΅ΠΉ ΡΠ°Π±ΠΎΡΠ°ΡΡ Ρ Π±ΠΎΠ»ΡΡΠΈΠΌΠΈ Π±Π°Π·Π°ΠΌΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ, Π±ΡΠ»Π° ΡΠ°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π° ΠΏΠ°ΡΠ°Π»Π»Π΅Π»ΡΠ½Π°Ρ Π²Π΅ΡΡΠΈΡ Π΄Π°Π½Π½ΠΎΠ³ΠΎ Π°Π»Π³ΠΎΡΠΈΡΠΌΠ°, ΠΊΠΎΡΠΎΡΠ°Ρ Π±ΡΠ»Π° ΡΠ΅Π°Π»ΠΈΠ·ΠΎΠ²Π°Π½Π° Π½Π° ΡΠ·ΡΠΊΠ΅ C++ Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ΠΌ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΏΠ°ΡΠ°Π»Π»Π΅Π»ΡΠ½ΠΎΠ³ΠΎ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ MPI ΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠΈΡΠΎΠ²Π°Π½Π° Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΡΠ΅ΡΡΡΡΠΎΠ² ΡΡΠΏΠ΅ΡΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΠΠΠ£ ΠΈΠΌΠ΅Π½ΠΈ Π.Π. ΠΠΎΠΌΠΎΠ½ΠΎΡΠΎΠ²Π°. ΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π½Π° Π±Π°Π·Π΅ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ Β«ΠΠ°Π±ΠΎΡΠΊΠΈΒ» ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ, ΡΡΠΎ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π½ΡΠΉ Π°Π»Π³ΠΎΡΠΈΡΠΌ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ Π½Π°ΠΉΡΠΈ ΡΡΠ°Π»ΠΎΠ½Π½ΡΡ ΠΎΡΡ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ Π·Π° Π²ΡΠ΅ΠΌΡ, ΠΏΡΠΈΠ΅ΠΌΠ»Π΅ΠΌΠΎΠ΅ Π΄Π»Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ Π±Π°Π·, ΡΠΎΡΡΠΎΡΡΠΈΡ
ΠΈΠ· ΡΠΎΡΠ΅Π½ ΠΈ ΡΡΡΡΡ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ, ΡΡΠΎ ΡΠ΄Π΅Π»Π°Π»ΠΎ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΡΠΌ Π΅Π³ΠΎ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ Π΄Π»Ρ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ°Π·ΠΌΠ΅ΡΠΊΠΈ Π±Π°Π· ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΎΡΠ»Π°Π΄ΠΊΠΈ ΠΈ ΡΠ΅ΡΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π½Π° Π½ΠΈΡ
ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π½ΡΡ
ΡΠ°Π½Π΅Π΅ Π°Π²ΡΠΎΡΠ°ΠΌΠΈ ΠΏΡΠΈΠ±Π»ΠΈΠΆΠ΅Π½Π½ΡΡ
ΠΏΡΠΎΡΠ΅Π΄ΡΡ ΠΏΠΎΠΈΡΠΊΠ° ΠΎΡΠΈ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΠΈ. Π Π°Π·ΡΠ°Π±ΠΎΡΠ°Π½Π½Π°Ρ ΠΏΠ°ΡΠ°Π»Π»Π΅Π»ΡΠ½Π°Ρ Π²Π΅ΡΡΠΈΡ ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ· ΠΏΡΠΈΠ±Π»ΠΈΠΆΠ΅Π½Π½ΡΡ
Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ² ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°Π΅Ρ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΠΏΡΠΈΠΊΠ»Π°Π΄Π½ΡΡ
Π·Π°Π΄Π°Ρ Π°Π½Π°Π»ΠΈΠ·Π° ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΠΉ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
, Π±Π»ΠΈΠ·ΠΊΠΈΡ
ΠΊ ΡΠ΅ΠΆΠΈΠΌΡ ΡΠ΅Π°Π»ΡΠ½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡ Π΄ΠΎΡΡΠΈΡΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ, ΠΈΡΡΠΈΡΠ»ΡΠ΅ΠΌΠΎΠ³ΠΎ Π² Π΄ΠΎΠ»ΡΡ
ΡΠ΅ΠΊΡΠ½Π΄Ρ Π΄Π°ΠΆΠ΅ Π½Π° ΠΎΠ±ΡΡΠ½ΡΡ
ΠΌΠ½ΠΎΠ³ΠΎΡΠ΄Π΅ΡΠ½ΡΡ
ΠΏΠ΅ΡΡΠΎΠ½Π°Π»ΡΠ½ΡΡ
ΠΊΠΎΠΌΠΏΡΡΡΠ΅ΡΠ°Ρ
, ΡΠΎΡ
ΡΠ°Π½ΡΡ ΠΏΡΠΈ ΡΡΠΎΠΌ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠ΅, Π»ΠΈΠ±ΠΎ Π±Π»ΠΈΠ·ΠΊΠΎΠ΅ ΠΊ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΌΡ ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎ ΡΠ΅ΡΠ΅Π½ΠΈΡ.Π Π°Π±ΠΎΡΠ° Π²ΡΠΏΠΎΠ»Π½Π΅Π½Π° ΠΏΡΠΈ ΠΏΠΎΠ΄Π΄Π΅ΡΠΆΠΊΠ΅ Π³ΡΠ°Π½ΡΠ° Π Π€Π€Π 16-57-52042
ALGORITHMS FOR ADJUSTMENT OF SYMMETRY AXIS FOUND FOR 2D SHAPES BY THE SKELETON COMPARISON METHOD
Reflection symmetry detection for 2D shapes is a well-known task in Computer Vision, but there is a limited number of efficient and effective methods for its solution. Our previously proposed approach based on pair-wise comparison of sub-sequences of skeleton primitives finds the axis of symmetry within few seconds. In order to evaluate the value of symmetry relative to the found axis we use the Jaccard similarity measure. It is applied to the pixels subsets of a shape which are split by the axis. Often an axis found by the skeleton comparison method diverges more or less from the ground-truth axis found by the method of exhaustive search among all the potential candidates. That is why the algorithms that allow adjusting the axis found by the fast skeleton method are proposed. They are based on the idea of searching the axis which is located near the seed skeleton axis and has greater Jaccard similarity measure. The experimental study on the βFlaviaβ and βButterfliesβ datasets shows that proposed algorithms find the ground-truth axis (or the axis which has slightly less Jaccard similarity value than the ground-truth axis) in near real time. It is considerably faster than any of the optimized brute-force methods