Package classer

Constants

For PixHausTest, PixRankHausTest and PixCorrelationScore the values should be or greater.

const (
    MaxDiffWidth  = 2
    MaxDiffHeight = 2
)

const (
    // MaxConnCompWidth is the default max cc width.
    MaxConnCompWidth = 350
    // MaxCharCompWidth is the default max char width.
    MaxCharCompWidth = 350
    // MaxWordCompWidth is the default max word width.
    MaxWordCompWidth = 1000
    // MaxCompHeight is the default max component height.
    MaxCompHeight = 120
)

JbAddedPixels is the size of the border added around pix of each c.c. for further processing.

const JbAddedPixels = 6

Variables

TwoByTwoWalk is the slice of values for classified encoding.

var TwoByTwoWalk = []int{
    0, 0,
    0, 1,
    -1, 0,
    0, -1,
    1, 0,
    -1, 1,
    1, 1,
    -1, -1,
    1, -1,
    0, -2,
    2, 0,
    0, 2,
    -2, 0,
    -1, -2,
    1, -2,
    2, -1,
    2, 1,
    1, 2,
    -1, 2,
    -2, 1,
    -2, -1,
    -2, -2,
    2, -2,
    2, 2,
    -2, 2,
}

type Classer ¶

Classer holds all the data accumulated during the classification process that can be used for a compressed jbig2-type representation of a set of images.

type Classer struct {
    // BaseIndex is number of components already processed on fully processed pages.
    BaseIndex int
    // Settings are current classer settings.
    Settings Settings

    // Number of components on each page - 'nacomps'- for each page added to the classer a new entry to the slice
    // is added with the value of components per page.
    ComponentsNumber *basic.IntSlice
    // Width * Height of each template without extra border pixels - 'naarea'.
    TemplateAreas *basic.IntSlice

    // Widths is max width of original src images.
    Widths map[int]int
    // Heights is max height of original src images.
    Heights map[int]int

    // NumberOfClasses is the current number of classes - 'nclass'.
    NumberOfClasses int
    // ClassInstances is the slice of bitmaps for each class. Unbordered - 'pixaa'.
    ClassInstances *bitmap.BitmapsArray
    // UndilatedTemplates for each class. Bordered and not dilated - 'pixat'.
    UndilatedTemplates *bitmap.Bitmaps
    // DilatedTemplates for each class. Bordered and dilated - 'pixatd'.
    DilatedTemplates *bitmap.Bitmaps

    // Hash table to find templates by their size - 'dahash'.
    TemplatesSize basic.IntsMap
    // FgTemplates - foreground areas of undilated templates. Used for rank < 1.0 - 'nafgt'.
    FgTemplates *basic.NumSlice

    // CentroidPoints centroids of all bordered cc.
    CentroidPoints *bitmap.Points
    // CentroidPointsTemplates centroids of all bordered template cc.
    CentroidPointsTemplates *bitmap.Points
    // ClassIDs is the slice of class ids for each component - 'naclass'.
    ClassIDs *basic.IntSlice
    // ComponentPageNumbers is the slice of page numbers for each component - 'napage'.
    // The index is the component id.
    ComponentPageNumbers *basic.IntSlice
    // PtaUL is the slice of UL corners at which the template
    // is to be placed for each component.
    PtaUL *bitmap.Points
    // PtaLL is the slice of LL corners at which the template
    // is to be placed for each component.
    PtaLL *bitmap.Points
}

func Init ¶

func Init(settings Settings) (*Classer, error)

Init initializes the classer with the provided settings.

func (*Classer) AddPage ¶

func (c *Classer) AddPage(inputPage *bitmap.Bitmap, pageNumber int, method Method) (err error)

AddPage adds the 'inputPage' to the classer 'c'.

func (*Classer) ComputeLLCorners ¶

func (c *Classer) ComputeLLCorners() (err error)

ComputeLLCorners computes the position of the LL (lower left) corners.

type Method ¶

Method is the encoding method used enum.

type Method int

enum definitions of the encoding methods.

const (
    RankHaus Method = iota
    Correlation
)

type Settings ¶

Settings keeps the settings for the classer.

type Settings struct {
    // MaxCompWidth is max component width allowed.
    MaxCompWidth int
    // MaxCompHeight is max component height allowed.
    MaxCompHeight int
    // SizeHaus is the size of square struct elem for hausdorf method.
    SizeHaus int
    // Rank val of hausdorf method match.
    RankHaus float64
    // Thresh is the threshold value for the correlation score.
    Thresh float64
    // Corrects thresh value for heavier components; 0 for no correction.
    WeightFactor float64
    // KeepClassInstances is a flag that defines if the class instances should be stored
    // in the 'ClassInstances' BitmapsArray.
    KeepClassInstances bool
    // Components is the setting the classification.
    Components bitmap.Component
    // Method is the encoding method.
    Method Method
}

func DefaultSettings ¶

func DefaultSettings() Settings

DefaultSettings returns default settings struct.

func (*Settings) SetDefault ¶

func (s *Settings) SetDefault()

SetDefault sets the default value for the settings.

func (Settings) Validate ¶

func (s Settings) Validate() error

Validate validates the settings input.