Using Image Encoders and Decoders

Windows GDI+ provides the Image class and the Bitmap class for storing images in memory and manipulating images in memory. GDI+ writes images to disk files with the help of image encoders and loads images from disk files with the help of image decoders. An encoder translates the data in an Image or Bitmap object into a designated disk file format. A decoder translates the data in a disk file to the format required by the Image and Bitmap objects. GDI+ has built-in encoders and decoders that support the following file types:

• BMP
• GIF
• JPEG
• PNG
• TIFF

GDI+ also has built-in decoders that support the following file types:

• WMF
• EMF
• ICON

The following topics discuss encoders and decoders in more detail:

• Listing Installed Encoders
• Listing Installed Decoders
• Retrieving the Class Identifier for an Encoder
• Determining the Parameters Supported by an Encoder
• Converting a BMP Image to a PNG Image
• Setting JPEG Compression Level
• Transforming a JPEG Image Without Loss of Information
• Creating and Saving a Multiple-Frame Image
• Copying Individual Frames from a Multiple-Frame Image