public void IndexedPixelsCollectionException()
{
ReportStart();
_pa = new PixelAnalysis( MakeBitmap( 10 ), QuantizerType.NeuQuant );
_pa.Analyse();
try
{
Assert.IsNull( _pa.IndexedPixelsCollection );
}
catch( InvalidOperationException ex )
{
string message
= "The PixelAnalysis object was instantiated using the "
+ "constructor which accepts a single image and you "
+ "are attempting to retrieve the indexed pixels for a "
+ "collection of images. "
+ "Call the IndexedPixels property instead.";
StringAssert.Contains( message, ex.Message );
ReportEnd();
throw;
}
}
private void TestMultipleImages( int numberOfColours )
{
_images.Add( MakeBitmap( numberOfColours ) );
_images.Add( MakeBitmap( numberOfColours ) );
_pa = new PixelAnalysis( _images );
_pa.Analyse();
CheckColourTable( numberOfColours );
CheckIndexedPixelsCollection( numberOfColours );
}
private void TestSingleImage( int numberOfColours, QuantizerType qt )
{
Bitmap image = MakeBitmap( numberOfColours );
_pa = new PixelAnalysis( image, qt );
_pa.Analyse();
CheckColourTable( numberOfColours );
CheckIndexedPixels( numberOfColours );
}
public void SingleImage257ColoursOctree()
{
ReportStart();
Bitmap image = MakeBitmap( 257 );
_pa = new PixelAnalysis( image, QuantizerType.Octree );
_pa.Analyse();
// FIXME: Octree quantizer is quantizing too much - reducing to 128 colours instead of 256
// TODO: Check for exactly 256 colours once Octree quantizer returns 256-colour images
// Assert.AreEqual( 256, _pa.ColourTable.Length );
Assert.LessOrEqual( _pa.ColourTable.Length, 256 );
Assert.AreEqual( image.Width * image.Height,
_pa.IndexedPixels.Count );
ReportEnd();
}
public void SingleImage257ColoursNeuQuant()
{
ReportStart();
Bitmap image = MakeBitmap( 257 );
_pa = new PixelAnalysis( image, QuantizerType.NeuQuant );
_pa.Analyse();
Assert.AreEqual( 256, _pa.ColourTable.Length );
Assert.AreEqual( image.Width * image.Height,
_pa.IndexedPixels.Count );
ReportEnd();
}
public void MultipleImages257Colours()
{
ReportStart();
_images.Add( MakeBitmap( 257 ) );
_images.Add( MakeBitmap( 257 ) );
_pa = new PixelAnalysis( _images );
_pa.Analyse();
// Cannot use the TestMultipleImages method this time because using
// more than 256 colours causes colour quantization to reduce it
// to 256 colours. Exact contents of colour table and indexed pixels
// are therefore unpredictable - we can only check their lengths.
Assert.AreEqual( 256, _pa.ColourTable.Length );
Assert.AreEqual( 2, _pa.IndexedPixelsCollection.Count );
Assert.AreEqual( _images[0].Width * _images[0].Height,
_pa.IndexedPixelsCollection[0].Count );
Assert.AreEqual( _images[1].Width * _images[1].Height,
_pa.IndexedPixelsCollection[1].Count );
ReportEnd();
}
/// <summary>
/// Writes a Logical Screen Descriptor to the supplied stream.
/// Also writes a global colour table if required.
/// </summary>
/// <param name="outputStream">
/// The stream to write to.
/// </param>
private void WriteLogicalScreenDescriptor( Stream outputStream )
{
bool hasGlobalColourTable = _strategy == ColourTableStrategy.UseGlobal;
int colourResolution = 7; // TODO: parameterise colourResolution?
bool globalColourTableIsSorted = false; // Sorting of colour tables is not currently supported
int backgroundColorIndex = 0; // TODO: parameterise backgroundColourIndex?
int pixelAspectRatio = 0; // TODO: parameterise pixelAspectRatio?
if( _strategy == ColourTableStrategy.UseGlobal )
{
if( _quantizerType == QuantizerType.UseSuppliedPalette )
{
// use supplied palette
_globalColourTable = new ColourTable();
string buildColourTableCounterText
= "Building colour table from supplied palette";
AddCounter( buildColourTableCounterText,
_palette.Count );
int paletteIndex = 0;
foreach( Color c in _palette )
{
_globalColourTable.Add( c );
MyProgressCounters[buildColourTableCounterText].Value
= paletteIndex;
paletteIndex++;
}
_globalColourTable.Pad();
RemoveCounter( buildColourTableCounterText );
}
else
{
// Analyse the pixels in all the images to build the
// global colour table.
Collection<Image> images = new Collection<Image>();
foreach( GifFrame thisFrame in _frames )
{
Image thisImage = thisFrame.TheImage;
images.Add( thisImage );
}
_pixelAnalysis = new PixelAnalysis( images );
_pixelAnalysis.ColourQuality = _quality;
_pixelAnalysis.Analyse();
_globalColourTable = _pixelAnalysis.ColourTable;
}
LogicalScreenDescriptor lsd =
new LogicalScreenDescriptor( _logicalScreenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
_globalColourTable.SizeBits,
backgroundColorIndex,
pixelAspectRatio );
lsd.WriteToStream( outputStream );
_globalColourTable.WriteToStream( outputStream );
}
else
{
LogicalScreenDescriptor lsd =
new LogicalScreenDescriptor( _logicalScreenSize,
hasGlobalColourTable,
colourResolution,
globalColourTableIsSorted,
7,
backgroundColorIndex,
pixelAspectRatio );
lsd.WriteToStream( outputStream );
}
}
private ColourTable SetActiveColourTable()
{
ColourTable act; // active colour table
if( _strategy == ColourTableStrategy.UseLocal )
{
if( _quantizerType == QuantizerType.UseSuppliedPalette )
{
if( _frames[_encodingFrame].Palette == null )
{
// TESTME: SetActiveColourTable - SetActiveColourTable, UseSuppliedPalette, no palette supplied
string message
= "You have opted to use a local colour table built "
+ "from a supplied palette, but frame "
+ _encodingFrame
+ "does not have a palette.";
throw new InvalidOperationException( message );
}
else
{
// Build local colour table from colours in the frame's
// supplied palette.
act = new ColourTable();
foreach( Color c in _frames[_encodingFrame].Palette )
{
act.Add( c );
}
act.Pad();
}
}
else
{
// Build local colour table based on colours in the image.
Image thisImage = _frames[_encodingFrame].TheImage;
_pixelAnalysis = new PixelAnalysis( thisImage,
_quantizerType );
_pixelAnalysis.ColourQuality = _quality;
_pixelAnalysis.Analyse();
// make local colour table active
act = _pixelAnalysis.ColourTable;
}
}
else
{
// make global colour table active
act = _globalColourTable;
}
return act;
}
