README

Lookup

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It is a nice, simple and fast library which helps you to lookup objects on a screen. It also includes OCR functionality. Using Lookup you can do OCR tricks like recognizing any information in your Robot application. Which can be useful for debugging or automating things.

This library is a port of this Java Lookup library to GoLang. Details on NCC (Normalized Cross Correlation) used by this library can be found in the original library's 'docs' folder (a lot of math).

Usage

Add this library to your project with:

go get github.com/deluan/lookup

To learn how to use it, take a look at the example files for Lookup and OCR. All images used in the examples are available in the testdata folder. For more details check the full documentation.

To Do:
  • Add basic LookUp function
  • Implement OCR
  • Optimize for speed
  • Clean-up API
  • Better docs
  • Implement Scaling
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Documentation

Overview

    Package lookup implements a nice, simple and fast library which helps you to lookup objects on a screen. It also includes OCR functionality. With Lookup you can do OCR tricks like recognizing any information in a screenshot from your Robot application. Which can be useful for debugging or automating things.

    This library is a port of the Java Lookup library (https://gitlab.com/axet/lookup) to GoLang. Details on NCC (Normalized Cross Correlation) used by this library can be found in the original library's docs folder (a lot of math).

    Example (Lookup)
    Output:
    
    Found 1 matches:
    - (21, 7) with 0.997942 accuracy
    
    Example (Ocr)
    Output:
    
    Text found in image: 3662
    32€/€
    

    Index

    Examples

    Constants

    This section is empty.

    Variables

    This section is empty.

    Functions

    This section is empty.

    Types

    type GPoint

    type GPoint struct {
    	X, Y int
    	G    float64
    }

      GPoint represents a match of a template inside an image.

      type Lookup

      type Lookup struct {
      	// contains filtered or unexported fields
      }

        Lookup implements a image search algorithm based on Normalized Cross Correlation. For an overview of the algorithm, see http://www.fmwconcepts.com/imagemagick/similar/index.php

        func NewLookup

        func NewLookup(image image.Image) *Lookup

          NewLookup creates a Lookup object. Lookup objects created by these function will do a gray scale search of the templates. Note that if the image or any template is not GrayScale, it will be converted automatically. This could cause some performance hits

          func NewLookupColor

          func NewLookupColor(image image.Image) *Lookup

            NewLookupColor creates a Lookup object that works with all color channels of the image (RGB). Keep in mind that Lookup objects created with this function can only accept color templates as parameters to the FindAll method

            func (*Lookup) FindAll

            func (l *Lookup) FindAll(template image.Image, threshold float64) ([]GPoint, error)

              FindAll searches for all occurrences of template inside the whole image.

              func (*Lookup) FindAllInRect

              func (l *Lookup) FindAllInRect(template image.Image, rect image.Rectangle, threshold float64) ([]GPoint, error)

                FindAllInRect searches for all occurrences of template only inside a part of the image. This can be used to speed up the search if you know the region of the image that the template should appear in.

                type OCR

                type OCR struct {
                	// contains filtered or unexported fields
                }

                  OCR implements a simple OCR based on the Lookup functions. It allows multiple fontsets, just call LoadFont for each fontset.

                  If you need to encode special symbols use UNICODE in the file name. For example if you need to have '\' character (which is prohibited in the path and file name) specify %2F.png as a image symbol name.

                  Sometimes you need to specify two different image for one symbol (if image / font symbol vary too much). To do so add unicode ZERO WIDTH SPACE symbol (%E2%80%8B) to the filename. Ex: %2F%E2%80%8B.png will produce '/' symbol as well.

                  func NewOCR

                  func NewOCR(threshold float64, numThreads ...int) *OCR

                    NewOCR creates a new OCR instance, that will use the given threshold. You can optionally parallelize the processing by specifying the number of threads to use. The optimal number varies and depends on your use case (size of fontset x size of image). Default is use only one thread

                    func (*OCR) LoadFont

                    func (o *OCR) LoadFont(fontPath string) error

                      LoadFont loads a specific fontset from the given folder. Fonts are simple image files containing a PNG/JPEG of the font, and named after the "letter" represented by the image.

                      This can be called multiple times, with different folders, to load different fontsets.

                      func (*OCR) Recognize

                      func (o *OCR) Recognize(img image.Image) (string, error)

                        Recognize the text in the image using the fontsets previously loaded. If a SubImage is received, the search will be limited by the boundaries of the SubImage