Using the ImageViewer classes

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Using the ImageViewer classes
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ImageViewer classes

• AboutDlg
• ChildFrame
• DlgTemplateBuilder
• InputDialog
• ImageViewer
• ImageData

• View
• CLUT
• MainFrame
• pnmHelper
• TIFFWriter
• Timer

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ImageViewer classes

• Most important classes
• ImageData (document)
• View (view)
• InputDialog
• pnmHelper
• TIFFWriter
• Timer

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ImageViewer classes

• ImageData class protected attributes
• mIsColor falsegray, truergb color
• mW, mH width and height
• mMin, mMax min and max values
• int mOriginalImage
• actual image pixel data
• stored mOriginalImage0 is gray
• or mOriginalImage0r, mOriginalImage1g,
  mOriginalImage2b
• 3 separate ints

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ImageViewer classes

• ImageData class public methods
• bool getIsColor ( void )
• int getW ( void ) int getH ( void )
• int getMin ( void ) int getMax ( void )
• int getData ( int i )
• int getGray ( int row, int col )
• int getRed ( int row, int col )
• int getGreen ( int row, int col )
• int getBlue ( int row, int col )
• Note that there arent any set methods!

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ImageViewer classes

• View class members
• unsigned char mDisplayData
• displayable image data
• stored b, g, r, 0
• 4 separate bytes
• Intel is little endian so this is actually
  0,r,g,b
• Note that ImageDatamOriginalImage is 1 int per
  component while ViewmImage is 1 byte per
  component.
• ImageData GetDocument()
• OnMouseMove ( ), OnDraw ( )

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ImageViewer classes

• View class OnDraw ( )
• CBitmap bm
• bm.CreateBitmap( pDoc-gtgetW(), pDoc-gtgetH(), 1,
  32, mDisplayData )
• pDC-gtBitBlt( 0, 0, pDoc-gtgetW(), pDoc-gtgetH(),
  dcMem, 0, 0, SRCCOPY )
• or
• pDC-gtStretchBlt( mTx, mTy,
• (int)(mScalepDoc-gtgetW()0.5),
• (int)(mScalepDoc-gtgetH()0.5), dcMem, 0, 0,
• pDoc-gtgetW(), pDoc-gtgetH(), SRCCOPY )

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ImageViewer classes

• pnmHelper class
• static int read_pnm_file (
• char fname, int w, int h,
• int samplesPerPixel, int min, int max )
• This method should be generally used to read any
  pnm (pgm grey, ppm color) binary or ASCII image
  files.

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ImageViewer classes

• pnmHelper class
• static void write_pgm_or_ppm_ascii_data (
• int buff, int width, int height,
• char fname, int samples_per_pixel )
• Write values as a pgm (grey) or ppm (color) ASCII
  file.

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ImageViewer classes

• TIFFWriter class
• static void write_tiff_data8_rgb (
• uint8 buff, int width, int height,
• FILE fp, bool use_clut,
• int samples_per_pixel )
• Write a 24-bit color tiff image.

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ImageViewer classes

• Timer class
• Can be used to easily time algorithms.
• Timer() ctor starts the timer.
• reset() resets the timer to 0 (and start the
  timer)
• getElapsedTime() returns a double of the elapsed
  time in seconds.
• getCPUTime() returns a double of the CPU time
  used in seconds.
• Visual Studio creates debug and release versions.
  Release is typically much faster than debug.

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Timer class for Java

• Ctor start timer.
• reset( ) starts timer back at zero.
• getElapsedTime() returns elapsed time resolved to
  milliseconds.
• Timer continues to run.
• getElapsedTimeNano() returns elapsed time
  resolved to nanoseconds.
• Timer continues to run.

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GUI Input (prompt user for a value)

• Java
• String value JOptionPane.showInputDialog(
• "Enter value " )
• C
• InputDialog dlg( "Enter a value )
• CString result dlg.m_str //get what user
  typed

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GUI output

• C
• AfxMessageBox presents a modal dialog box to the
  user with a programmer-specified string.
• Java
• See JOptionPane.showMessageDialog( )

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Misc. C review topics output

• printf
• Must first include ltstdio.hgt
• int i 5242
• printf( The value d\nis x in hex.\n, i, i )
• double d 65.769970
• printf( The std dev f., d )
• char name Istvan
• printf( Mr. s, you have .2f in your account.,
• str, d )

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Misc. C review topics converting numbers to
strings

• sprintf
• Just like printf but works on a string buffer in
  memory.
• char buff 256
• sprintf( buff,
• Mr. s, you have .2f in your account.,
• str, d )
• AfxMessageBox( buff )

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Misc. C review topics memory management

• malloc/free
• int iptr (int) malloc( 1000 sizeof(int) )
• //what if iptr NULL?
• for (int i0 ilt1000 i)
• iptri i
• free( iptr ) //must do this or memory leaks
  occur!
• iptr NULL //just to be extra careful

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Misc. C review topics assert

• assert
• Assume or require some condition to be true.
• Now in Java 5 as well!
• int iptr (int) malloc( 1000 sizeof(int) )
• //what if iptr NULL?
• assert( iptr ! NULL )
• Disappears completely in non-debug mode.

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Misc. C review topics number input

• InputDialog dlg("Enter a value ")
• How can we check and convert what the user typed
  (a number)?
• int x
• int howManyWereOK sscanf( dlg.m_str, "d", x
  )
• if (howManyWereOK!1)
• AfxMessageBox( Bad input. )
• else
• . . .

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Misc. Java review topics number input

• String value JOptionPane.showInputDialog(
• "Enter value " )
• How can we check and convert what the user typed
  (a number)?
• boolean inputOKtrue
• int x
• try
• x Integer.parseInt( value )
• catch (Exception e)
• inputOKfalse
• if (!inputOK)
• . . .
• else
• . . .

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Misc. Java review topics octal numbers

• String value JOptionPane.showInputDialog(
• "Enter value " )
• Octal support.
• int xy 09
• Compiler error integer number too large.
• int jj 0123
• System.out.println( jj )
• 83

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Sample images

• Available on main course web page.