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EncoderParameter Class

Used to pass a value, or an array of values, to an image encoder.

System.Object
  System.Drawing.Imaging.EncoderParameter

Namespace:  System.Drawing.Imaging
Assembly:  System.Drawing (in System.Drawing.dll)
public sealed class EncoderParameter : IDisposable

The EncoderParameter type exposes the following members.

  NameDescription
Public methodEncoderParameter(Encoder, Byte)Initializes a new instance of the EncoderParameter class with the specified Encoder object and one unsigned 8-bit integer. Sets the ValueType property to ValueTypeByte, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Byte[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and an array of unsigned 8-bit integers. Sets the ValueType property to ValueTypeByte, and sets the NumberOfValues property to the number of elements in the array.
Public methodEncoderParameter(Encoder, Int16)Initializes a new instance of the EncoderParameter class with the specified Encoder object and one, 16-bit integer. Sets the ValueType property to ValueTypeShort, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Int16[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and an array of 16-bit integers. Sets the ValueType property to ValueTypeShort, and sets the NumberOfValues property to the number of elements in the array.
Public methodEncoderParameter(Encoder, Int64)Initializes a new instance of the EncoderParameter class with the specified Encoder object and one 64-bit integer. Sets the ValueType property to ValueTypeLong (32 bits), and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Int64[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and an array of 64-bit integers. Sets the ValueType property to ValueTypeLong (32-bit), and sets the NumberOfValues property to the number of elements in the array.
Public methodEncoderParameter(Encoder, String)Initializes a new instance of the EncoderParameter class with the specified Encoder object and a character string. The string is converted to a null-terminated ASCII string before it is stored in the EncoderParameter object. Sets the ValueType property to ValueTypeAscii, and sets the NumberOfValues property to the length of the ASCII string including the NULL terminator.
Public methodEncoderParameter(Encoder, Byte, Boolean)Initializes a new instance of the EncoderParameter class with the specified Encoder object and one 8-bit value. Sets the ValueType property to ValueTypeUndefined or ValueTypeByte, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Byte[], Boolean)Initializes a new instance of the EncoderParameter class with the specified Encoder object and an array of bytes. Sets the ValueType property to ValueTypeUndefined or ValueTypeByte, and sets the NumberOfValues property to the number of elements in the array.
Public methodEncoderParameter(Encoder, Int32, Int32)Initializes a new instance of the EncoderParameter class with the specified Encoder object and a pair of 32-bit integers. The pair of integers represents a fraction, the first integer being the numerator, and the second integer being the denominator. Sets the ValueType property to ValueTypeRational, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Int32[], Int32[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and two arrays of 32-bit integers. The two arrays represent an array of fractions. Sets the ValueType property to ValueTypeRational, and sets the NumberOfValues property to the number of elements in the numerator array, which must be the same as the number of elements in the denominator array.
Public methodEncoderParameter(Encoder, Int64, Int64)Initializes a new instance of the EncoderParameter class with the specified Encoder object and a pair of 64-bit integers. The pair of integers represents a range of integers, the first integer being the smallest number in the range, and the second integer being the largest number in the range. Sets the ValueType property to ValueTypeLongRange, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Int64[], Int64[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and two arrays of 64-bit integers. The two arrays represent an array integer ranges. Sets the ValueType property to ValueTypeLongRange, and sets the NumberOfValues property to the number of elements in the rangebegin array, which must be the same as the number of elements in the rangeend array.
Public methodEncoderParameter(Encoder, Int32, Int32, Int32)Initializes a new instance of the EncoderParameter class with the specified Encoder object and three integers that specify the number of values, the data type of the values, and a pointer to the values stored in the EncoderParameter object.
Public methodEncoderParameter(Encoder, Int32, Int32, Int32, Int32)Initializes a new instance of the EncoderParameter class with the specified Encoder object and four, 32-bit integers. The four integers represent a range of fractions. The first two integers represent the smallest fraction in the range, and the remaining two integers represent the largest fraction in the range. Sets the ValueType property to ValueTypeRationalRange, and sets the NumberOfValues property to 1.
Public methodEncoderParameter(Encoder, Int32[], Int32[], Int32[], Int32[])Initializes a new instance of the EncoderParameter class with the specified Encoder object and four arrays of 32-bit integers. The four arrays represent an array rational ranges. A rational range is the set of all fractions from a minimum fractional value through a maximum fractional value. Sets the ValueType property to ValueTypeRationalRange, and sets the NumberOfValues property to the number of elements in the numerator1 array, which must be the same as the number of elements in the other three arrays.
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  NameDescription
Public propertyEncoderGets or sets the Encoder object associated with this EncoderParameter object. The Encoder object encapsulates the globally unique identifier (GUID) that specifies the category (for example Quality, ColorDepth, or Compression) of the parameter stored in this EncoderParameter object.
Public propertyNumberOfValuesGets the number of elements in the array of values stored in this EncoderParameter object.
Public propertyTypeGets the data type of the values stored in this EncoderParameter object.
Public propertyValueTypeGets the data type of the values stored in this EncoderParameter object.
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  NameDescription
Public methodDisposeReleases all resources used by this EncoderParameter object.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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You can also use an EncoderParameter object to receive a list of possible values supported by a particular parameter of a particular image encoder.

The following code example demonstrates how to create a EncoderParameter using the EncoderParameter constructor. To run this example, paste the code into a Windows Form and call the VaryQualityLevel method from the form's constructor. This example requires an image file named TestPhoto.jpg located at c:\.


private void VaryQualityLevel()
{
    // Get a bitmap.
    Bitmap bmp1 = new Bitmap(@"c:\TestPhoto.jpg");
    ImageCodecInfo jgpEncoder = GetEncoder(ImageFormat.Jpeg);

    // Create an Encoder object based on the GUID
    // for the Quality parameter category.
    System.Drawing.Imaging.Encoder myEncoder =
        System.Drawing.Imaging.Encoder.Quality;

    // Create an EncoderParameters object.
    // An EncoderParameters object has an array of EncoderParameter
    // objects. In this case, there is only one
    // EncoderParameter object in the array.
    EncoderParameters myEncoderParameters = new EncoderParameters(1);

    EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, 50L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityFifty.jpg", jgpEncoder, myEncoderParameters);

    myEncoderParameter = new EncoderParameter(myEncoder, 100L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityHundred.jpg", jgpEncoder, myEncoderParameters);

    // Save the bitmap as a JPG file with zero quality level compression.
    myEncoderParameter = new EncoderParameter(myEncoder, 0L);
    myEncoderParameters.Param[0] = myEncoderParameter;
    bmp1.Save(@"c:\TestPhotoQualityZero.jpg", jgpEncoder, myEncoderParameters);

}


...


private ImageCodecInfo GetEncoder(ImageFormat format)
{

    ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();

    foreach (ImageCodecInfo codec in codecs)
    {
        if (codec.FormatID == format.Guid)
        {
            return codec;
        }
    }
    return null;
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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