Features for handwriting recognition

| *The challengeRappt JD 10 Feb no 175, om machtiging om af

| *Short processing pipelinemachtigingFeature extractionClassification82,34,66,0.12machtigingLearning

| *Processing pipelineFeature extractionClassificationPreprocessing

| *Input image types

Color:

Grayscale:

Binary:

PreprocessingGoal: enhance the foreground while reducing other visual symptoms (stains, noise, pictures, ...)Methods:Contrast stretchingHighpass filteringDespecklingChange color representation (RGB, HSV, grayscale, black/white, )Remove selected connected components () | *

| *Connected components

| *Processing pipelineSegmentationFeature extractionClassificationPreprocessing

| *Object of classificationSentencesWordsCharacters

(use grammar)(use dictionary)(use alphabet)

| *Object representationsImageUnordered vectors (in a coco)Contour vectorsOn-line vectorsSkeleton imageSkeleton vectors

(x, y)i(x, y)k(x, y)k(x, y)kI(x, y)I(x, y)

| *A full processing pipelineSegmentationNormalizationFeature extractionClassificationPreprocessing

| *InvarianceLuminance / contrastPositionSizeRotationShearWriter styleInk thickness

| *Invariance by normalizationLuminance / contrastPositionSizeRotationShearWriter styleInk thicknessCenter on center of gravityContrast stretchingScale to standard size

| *Invariance by trying many deformationsLuminance / contrastPositionSizeRotationShearWriter styleInk thicknessTry different scale factorsTry different rotations and use the best recognition resultTry different deformations

| *Invariance by using invariant featuresLuminance / contrastPositionSizeRotationShearWriter styleInk thicknessZernike invariant moments

| *A full processing pipelineSegmentationNormalizationFeature extractionClassificationPreprocessing82,34,66,

| *Feature ROI typesWhole objectZonesWindowing

| *Whole object (wholistic)

| *Zones

| *Windowing

| *Feature typesImage itselfStatisticalStructuralAbstract

Image (off-line) features (120)Contour / on-line features (21 28)

| *Feature 1 3Connected component images

Scaled image

Distance transform

(on whiteboard)

| *Feature 4: density histogram

| *Feature 5: radon transform

| *Feature 6: run count pattern36

| *Feature 7: run length patternavgstdev

| *Feature 8: Autocorrelation

| *Feature 9: Polar zones

| *Feature 10: radial zones (tip!)

| *Feature 11: zone histograms

Feature 12: Hinge | *(By Marius Bulacu)

Feature 13: Fraglets | *

| *RegelmatighedenSingulariteitenFeature 14: J.C. Simon (1/2)

| *"million" ==> convex:concave:3(north:concave) :(north:LOOP):concave:(north:LOOP) :concave:north :concave:HOLE :2(convex:concave)(J.-C. Simon, 1989)Feature 14: J.C. Simon (2/2)

| *Feature 15: Structure of background (1/3)

| *Feature 15: Structure of background (2/3)

| *Feature 15: Structure of background (3/3)

| *Feature 16: Structure of foreground + background

| *Feature 17: Fourier transform (1/2)From: http://ccp.uchicago.edu/~dcbradle/pages/5.23.06.html

| *Feature 17: Fourier transform (2/2)Fig. 1 and 3 from: http://www.csse.uwa.edu.au/~wongt/matlab.htmlFig. 2 from: http://www.chemicool.com/definition/fourier_transform.html

| *Feature 18: Wavelet transformFrom: http://www.regonaudio.com/Audio%20Measurement%20via%20Wavelets.html

| *Feature 19: Hu invariant momentsarea of the objectcenter of massSlide from: http://www.cedar.buffalo.edu/~govind/CSE717/lectures/CSE717_3.pptInvariant for scale, position and rotationDerived from momentsMoments describe the image distribution with respect to its axes Works on (x, y) vectors

| *Feature 20: Zernike momentsFrom: Trier, O. D., Jain, A. K., and Taxt, T. (1996). Feature extraction methods for character recognition - a survey. Pattern Recognition,29:641662.

| *Feature 21 28: Contour features(cos, sin) of running angle(cos, sin) of running angular differenceAngular differenceFourier transformInk density (horizontal or vertical)Radon transform: (ink density, computed radially from the c.o.g.)Angular histogramCurvature scale space ()

| *Feature 28: Curvature scale spaceFrom: http://www.christine.oppe.info/blog/category/formen-und-farben/formenvergleich/positeration

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