Mstr
This program uses the String Reader module to define a font from an image containing a mosaic of Quebec license plates. Two String Models are then defined and parameterized to read only some valid Quebec license plates. A license plate reading is then performed in a target image of a car on the road.
Language: C++
Functions used: MappAlloc, MappFree, MappTimer, MbufFree, MbufLoad, MbufRestore, MdispAlloc, MdispControl, MdispFree, MdispInquire, MdispSelect, MstrAlloc, MstrAllocResult, MstrControl, MstrDraw, MstrEditFont, MstrFree, MstrGetResult, MstrPreprocess, MstrRead, MstrSetConstraint, MsysAlloc, MsysFree
Categories: Overview, General, Industries, Surveillance/ITS, Applications, ANPR/LPR, Modules, Buffer, Display, Graphics, String Reader, What's New, Older, AIL 10.0 U94
///////////////////////////////////////////////////////////////////////////////
// Aurora Imaging Library
// Filename: MStr.cpp
//
// Description: This program uses the String Reader module to define a font
// from an image containing a mosaic of Quebec license plates.
// Two String Models are then defined and parameterized to read
// only some valid Quebec license plates.
// A license plate reading is then performed in a target image
// of a car on the road.
//
// (C) 1992-2026 Zebra Technologies Corp. and/or its affiliates
// All Rights Reserved
///////////////////////////////////////////////////////////////////////////////
#include <AIL.h>
// Image file specifications.
#define IMAGE_FILE_DEFINITION M_IMAGE_PATH AIL_TEXT("QcPlates.mim")
#define IMAGE_FILE_TO_READ M_IMAGE_PATH AIL_TEXT("LicPlate.mim")
// String containing all characters used for font definition.
#define TEXT_DEFINITION "AVS300CVK781JNK278 EBX380QKN918HCC839 "\
"YRH900ZQR756977AMQ GPK742389EYE569ESQ"
// Font normalization size Y.
#define NORMALIZATION_SIZE_Y 20L
// Max size of plate string.
#define STRING_MAX_SIZE 32L
//*****************************************************************************
// Main.
int MosMain(void)
{
AIL_ID AilApplication, // Application identifier.
AilSystem, // System identifier.
AilDisplay, // Display identifier.
AilImage, // Image buffer identifier.
AilOverlayImage, // Overlay image.
AilStrContext, // String context identifier.
AilStrResult; // String result buffer identifier.
AIL_INT NumberOfStringRead; // Total number of strings to read.
AIL_DOUBLE Score; // String score.
AIL_TEXT_CHAR StringResult[STRING_MAX_SIZE+1]; // String of characters read.
AIL_DOUBLE Time = 0.0; // Time variable.
// Print module name.
MosPrintf(AIL_TEXT("\nSTRING READER MODULE:\n"));
MosPrintf(AIL_TEXT("---------------------\n\n"));
// Allocate defaults
MappAllocDefault(M_DEFAULT, &AilApplication, &AilSystem, &AilDisplay, M_NULL, M_NULL);
// Restore the font definition image
MbufRestore(IMAGE_FILE_DEFINITION, AilSystem, &AilImage);
// Display the image and prepare for overlay annotations.
MdispSelect(AilDisplay, AilImage);
MdispControl(AilDisplay, M_OVERLAY, M_ENABLE);
MdispInquire(AilDisplay, M_OVERLAY_ID, &AilOverlayImage);
// Allocate a new empty String Reader context.
MstrAlloc( AilSystem, M_FONT_BASED, M_DEFAULT, &AilStrContext);
// Allocate a new empty String Reader result buffer.
MstrAllocResult(AilSystem, M_DEFAULT, &AilStrResult);
// Add a new empty user defined font to the context.
MstrControl(AilStrContext, M_CONTEXT, M_FONT_ADD, M_USER_DEFINED);
// Add user-defined characters from the license plate mosaic image.
// Note that the string that identifies the character values to associate with the
// character representations (TEXT_DEFINITION) includes repeated character values
// (e.g. 'E'); each instance of a repeated character value causes the character
// representation associated with this value to be overwritten.
MstrEditFont(AilStrContext, M_FONT_INDEX(0), M_CHAR_ADD,
M_USER_DEFINED + M_FOREGROUND_BLACK,
AilImage, (void *)TEXT_DEFINITION, M_NULL);
// Draw all the characters in the font in the overlay image.
// Note that since M_ORIGINAL is specified, characters are drawn at the location
// from which they were originally extracted from the license plate mosaic image.
// This allows you to see which character representation was used for a repeated
// character value in TEXT_DEFINITION.
MgraControl(M_DEFAULT, M_COLOR, M_COLOR_GREEN);
MstrDraw(M_DEFAULT, AilStrContext, AilOverlayImage, M_DRAW_CHAR,
M_FONT_INDEX(0), M_NULL, M_ORIGINAL);
// Normalize the characters of the font to an appropriate size.
MstrEditFont(AilStrContext, M_FONT_INDEX(0), M_CHAR_NORMALIZE,
M_SIZE_Y, NORMALIZATION_SIZE_Y, M_NULL, M_NULL);
// Add 2 new empty strings models to the context for the 2 valid types of
// plates (3 letters followed by 3 numbers or 3 numbers followed by 3 letters)
// Note that the read time increases with the number of strings in the context.
MstrControl(AilStrContext, M_CONTEXT, M_STRING_ADD, M_USER_DEFINED);
MstrControl(AilStrContext, M_CONTEXT, M_STRING_ADD, M_USER_DEFINED);
// Set number of strings to read.
MstrControl(AilStrContext, M_CONTEXT, M_STRING_NUMBER, 1);
// Set number of expected characters for all string models to 6 characters.
MstrControl(AilStrContext, M_STRING_INDEX(M_ALL), M_STRING_SIZE_MIN, 6);
MstrControl(AilStrContext, M_STRING_INDEX(M_ALL), M_STRING_SIZE_MAX, 6);
// Set default constraint to uppercase letter for all string models
MstrSetConstraint(AilStrContext, M_STRING_INDEX(0), M_DEFAULT,
M_LETTER + M_UPPERCASE, M_NULL );
MstrSetConstraint(AilStrContext, M_STRING_INDEX(1), M_DEFAULT,
M_LETTER + M_UPPERCASE, M_NULL );
// Set constraint of 3 last characters to digit for the first string model
MstrSetConstraint(AilStrContext, M_STRING_INDEX(0), 3, M_DIGIT, M_NULL );
MstrSetConstraint(AilStrContext, M_STRING_INDEX(0), 4, M_DIGIT, M_NULL );
MstrSetConstraint(AilStrContext, M_STRING_INDEX(0), 5, M_DIGIT, M_NULL );
// Set constraint of 3 first characters to digit for the second string model
MstrSetConstraint(AilStrContext, M_STRING_INDEX(1), 0, M_DIGIT, M_NULL );
MstrSetConstraint(AilStrContext, M_STRING_INDEX(1), 1, M_DIGIT, M_NULL );
MstrSetConstraint(AilStrContext, M_STRING_INDEX(1), 2, M_DIGIT, M_NULL );
// Pause to show the font definition.
MosPrintf(AIL_TEXT("This program has defined a font with this ")
AIL_TEXT("Quebec plates mosaic image.\n"));
MosPrintf(AIL_TEXT("Press any key to continue.\n\n"));
MosGetch();
// Clear the display overlay.
MdispControl(AilDisplay, M_OVERLAY_CLEAR, M_DEFAULT);
// Load image to read into image buffer.
MbufLoad(IMAGE_FILE_TO_READ, AilImage);
// Preprocess the String Reader context.
MstrPreprocess(AilStrContext, M_DEFAULT);
// Dummy first call for bench measure purpose only (bench stabilization,
// cache effect, etc...). This first call is NOT required by the application.
MstrRead(AilStrContext, AilImage, AilStrResult);
// Reset the timer.
MappTimer(M_DEFAULT, M_TIMER_RESET+M_SYNCHRONOUS, M_NULL);
// Perform the read operation on the specified target image.
MstrRead(AilStrContext, AilImage, AilStrResult);
// Read the time.
MappTimer(M_DEFAULT, M_TIMER_READ+M_SYNCHRONOUS, &Time);
// Get number of strings read and show the result.
MstrGetResult(AilStrResult, M_GENERAL, M_STRING_NUMBER + M_TYPE_AIL_INT,
&NumberOfStringRead);
if( NumberOfStringRead >= 1)
{
MosPrintf(AIL_TEXT("The license plate was read successfully (%.2lf ms)\n\n"),
Time*1000 );
// Draw read result.
MgraControl(M_DEFAULT, M_COLOR, M_COLOR_BLUE);
MstrDraw(M_DEFAULT, AilStrResult, AilOverlayImage, M_DRAW_STRING, M_ALL,
M_NULL, M_DEFAULT);
MgraControl(M_DEFAULT, M_COLOR, M_COLOR_GREEN);
MstrDraw(M_DEFAULT, AilStrResult, AilOverlayImage, M_DRAW_STRING_BOX, M_ALL,
M_NULL, M_DEFAULT);
// Print the read result.
MosPrintf(AIL_TEXT(" String Score\n") );
MosPrintf(AIL_TEXT(" -----------------------------------\n") );
MstrGetResult(AilStrResult, 0, M_STRING+M_TYPE_TEXT_CHAR, StringResult);
MstrGetResult(AilStrResult, 0, M_STRING_SCORE, &Score);
MosPrintf(AIL_TEXT(" %s %.1lf\n"), StringResult, Score );
}
else
{
MosPrintf(AIL_TEXT("Error: Plate was not read.\n"));
}
// Pause to show results.
MosPrintf(AIL_TEXT("\nPress any key to end.\n\n"));
MosGetch();
// Free all allocations.
MstrFree(AilStrContext);
MstrFree(AilStrResult);
MbufFree(AilImage);
// Free defaults.
MappFreeDefault(AilApplication, AilSystem, AilDisplay, M_NULL, M_NULL);
return 0;
}