sudoku downloader and recognizer

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Post on 23-Feb-2016




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Sudoku Downloader and Recognizer. Author : Pedro Evaristo Gonzlez Snchez. Main Activity ( Portrait ). Recognizement. Custom View. Gaming. Backtracking. Board Downloader. Custom view. Paint and Canvas to draw , background , lines and numbers Adaptable ( OnSizeChanged ) - PowerPoint PPT Presentation


Sudoku Downloader and Recognizer

Sudoku Downloader and RecognizerAuthor: Pedro Evaristo Gonzlez Snchez

Main Activity(Portrait)RecognizementCustom ViewGamingBacktrackingBoard DownloaderCustom view

Paint and Canvas to draw, background, lines and numbers

Adaptable ( OnSizeChanged )

Events Self-management( onTouchEvent, onKeypressed )

Interaction with Main Activity

Custom View Main ActivityMain Activity instances Custom View

Main activity set sensorials methods of the Custom View (Focusable)

Whether a Button number is pressed, Main Activity recieves the actual cell position iluminated

Main Activity updates the Sudoku Board and order the custom view to be painted onDraw() and invalidate() )

Class Sudoku (I)Matrix [9][9] of Integers

Constructor overload ( String ) to implement the communication between activities

The class return a String which contains the sudoku board. This is very helpful for several situations. For innstance ( Bundle and Activities communication)

Neighbor checking ( row, column and block )

Sudoku Class II ( Backtracking )If the actual Cell is (9,9) => Ends

If you find a number, go to the next cell ( Original Sudoku )

For each value 1..9

If neighbor checking is positiveSudoku(i+1,j+1)

If you dont find a candidate, restore and go back one cellDownload Activity (I)A way to update the app game

It exist a Sudoku board holded in a web server

Good formed Board within a *.txt file.

The goal is to rescue this board and take it to the Game

Download Activity (II)

3. Sudoku Recognizer3.0 Android previous concepts

3.1 Image Capture

3.2 Image processing (OpenCV)

3.3 Optical Chracter Recognition (OCR)Tesseract3.0 Android previous conceptsSDK and OpenCV Library (OpenCV)

NDK (Native Developing Kit) ( Tesseract )Build libraries and reference them in the application.

3.1 Image Capture

Calling the Intent in charge of capturing images of Android

Capture and save the image in a temporal file

Pre-processing => Finding the balance between good qualitiy and computability

3.2 Image Processing (I)First controversy, the image is in perspective => the board is not a quad, is a trapezoid

The Main concern is a processing in two levels (RGB and GRAY)

Borders detection

Next, searching the biggest contour within the image. (ROI)

Image Processing (II)

Image Processing (III)Hough algorithm and transform to find the boards linesTwo fundamental concepts in line processing:Every single line will be delete painting them of white or black in each case (RGB and GRAY).Check if the start point or end point of line is inside some of the four rect corners of the image

Image Processing (IV)Getting the matrix that defines the perspective transformation needed to extrapolate the corners of the board to the corners of the image

Apply a WarpPerspective Transformation with the matriz obtained.

Image Processing (V)At this point, the board is divided in equal cells to process each one of them

Procesamiento de la Imagen (VI)Single cell processing in paralell (RGB and Gray) bearing in mind Tesseracts requeriments.

Equalizing Histogram


Smooth + DilatefindContours()Tesseract ( OCR )Dont wait for a miracle!. You need an strong image processing

Delimiting dictionary to numbers (1..9)

For each number it is necessary releasing the memory allocated by the image and by the tesseracts object. We are on a phone and weve got less memory resources.

Tesseract6Thats all. Thank you!!