README
¶
Lookup
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 the Java Lookup library to GoLang. Details of 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 functionImplement OCROptimize for speedClean-up APIBetter docs- Implement Scaling
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) ¶
package main
import (
"fmt"
"image"
"os"
_ "image/png"
"github.com/deluan/lookup"
)
// Helper function to load an image from the filesystem
func loadImage(imgPath string) image.Image {
imageFile, _ := os.Open(imgPath)
defer imageFile.Close()
img, _, _ := image.Decode(imageFile)
return img
}
func main() {
// Load full image
img := loadImage("testdata/cyclopst1.png")
// Create a lookup for that image
l := lookup.NewLookup(img)
// Load a template to search inside the image
template := loadImage("testdata/cyclopst3.png")
// Find all occurrences of the template in the image
pp, _ := l.FindAll(template, 0.9)
// Print the results
if len(pp) > 0 {
fmt.Printf("Found %d matches:\n", len(pp))
for _, p := range pp {
fmt.Printf("- (%d, %d) with %f accuracy\n", p.X, p.Y, p.G)
}
} else {
println("No matches found")
}
}
Output: Found 1 matches: - (21, 7) with 0.997942 accuracy
Example (Ocr) ¶
package main
import (
"fmt"
"image"
"os"
_ "image/png"
"github.com/deluan/lookup"
)
// Helper function to load an image from the filesystem
func loadImageFromFile(imgPath string) image.Image {
imageFile, _ := os.Open(imgPath)
defer imageFile.Close()
img, _, _ := image.Decode(imageFile)
return img
}
func main() {
// Create an OCR object with an accuracy of 0.7
ocr := lookup.NewOCR(0.7)
// Load a fontSet
_ = ocr.LoadFont("testdata/font_1")
// Load an image to recognize
img := loadImageFromFile("testdata/test3.png")
// Recognize text in image
text, _ := ocr.Recognize(img)
// Print the results
fmt.Printf("Text found in image: %s\n", text)
}
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 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 ¶
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 ¶
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) FindAllInRect ¶ added in v0.0.3
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 ¶
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
Source Files