Module java.desktop

Class BMPImageWriteParam


public class BMPImageWriteParam extends ImageWriteParam
A subclass of ImageWriteParam for encoding images in the BMP format.

This class allows for the specification of various parameters while writing a BMP format image file. By default, the data layout is bottom-up, such that the pixels are stored in bottom-up order, the first scanline being stored last.

The particular compression scheme to be used can be specified by using the setCompressionType() method with the appropriate type string. The compression scheme specified will be honored if and only if it is compatible with the type of image being written. If the specified compression scheme is not compatible with the type of image being written then the IOException will be thrown by the BMP image writer. If the compression type is not set explicitly then getCompressionType() will return null. In this case the BMP image writer will select a compression type that supports encoding of the given image without loss of the color resolution.

The compression type strings and the image type(s) each supports are listed in the following table:

Compression Types
Type String Description Image Types
BI_RGB Uncompressed RLE <= 8-bits/sample
BI_RLE8 8-bit Run Length Encoding <= 8-bits/sample
BI_RLE4 4-bit Run Length Encoding <= 4-bits/sample
BI_BITFIELDS Packed data 16 or 32 bits/sample
  • Constructor Details

    • BMPImageWriteParam

      public BMPImageWriteParam(Locale locale)
      Constructs a BMPImageWriteParam set to use a given Locale and with default values for all parameters.
      locale - a Locale to be used to localize compression type names and quality descriptions, or null.
    • BMPImageWriteParam

      public BMPImageWriteParam()
      Constructs an BMPImageWriteParam object with default values for all parameters and a null Locale.
  • Method Details

    • setTopDown

      public void setTopDown(boolean topDown)
      If set, the data will be written out in a top-down manner, the first scanline being written first.
      topDown - whether the data are written in top-down order.
    • isTopDown

      public boolean isTopDown()
      Returns the value of the topDown parameter. The default is false.
      whether the data are written in top-down order.