Convert from BufferedImage to SWT File

Question

After a long search, I found some code that converts a BufferedImage to a SWT image (no need to read it yet):

 public static ImageData convertToSWT(BufferedImage bufferedImage) { if (bufferedImage.getColorModel() instanceof DirectColorModel) { DirectColorModel colorModel = (DirectColorModel) bufferedImage.getColorModel(); PaletteData palette = new PaletteData( colorModel.getRedMask(), colorModel.getGreenMask(), colorModel.getBlueMask() ); ImageData data = new ImageData( bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette ); WritableRaster raster = bufferedImage.getRaster(); int[] pixelArray = new int[3]; for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { raster.getPixel(x, y, pixelArray); int pixel = palette.getPixel( new RGB(pixelArray[0], pixelArray[1], pixelArray[2]) ); data.setPixel(x, y, pixel); } } return data; } else if (bufferedImage.getColorModel() instanceof IndexColorModel) { IndexColorModel colorModel = (IndexColorModel) bufferedImage.getColorModel(); int size = colorModel.getMapSize(); byte[] reds = new byte[size]; byte[] greens = new byte[size]; byte[] blues = new byte[size]; colorModel.getReds(reds); colorModel.getGreens(greens); colorModel.getBlues(blues); RGB[] rgbs = new RGB[size]; for (int i = 0; i < rgbs.length; i++) { rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF); } PaletteData palette = new PaletteData(rgbs); ImageData data = new ImageData( bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette ); data.transparentPixel = colorModel.getTransparentPixel(); WritableRaster raster = bufferedImage.getRaster(); int[] pixelArray = new int[1]; for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { raster.getPixel(x, y, pixelArray); data.setPixel(x, y, pixelArray[0]); } } return data; } return null; } 

(found here: http://www.java2s.com/Code/Java/SWT-JFace-Eclipse/ConvertsabufferedimagetoSWTImageData.htm ).

I tested it and it works great. The problem is that I do not understand this (I believe that it uses raw data interfaces as for transfer). It occurred to me that a much simpler solution would be to write a BufferedImage out before ByteArrayOutputStream and then read it back into a SWT image using ByteArrayInputStream . Are there any problems with this solution? How about speed?

This conversion is necessary because all image resizing libraries exist for AWT, and yet I display the image using SWT.

Thanks!

Answer 1

The complexity of the code is mainly due to the two possible color models of BufferedImage . I don’t think you can improve much. First of all, using an intermediate Stream will require that the two image systems have a common format, and converting to / from a Stream will definitely be slower than the current code.

Answer 2

This is a more complete version ... The one that was posted in the question does not work for me.

 /** * snippet 156: convert between SWT Image and AWT BufferedImage. * <p> * For a list of all SWT example snippets see * http://www.eclipse.org/swt/snippets/ */ public static ImageData convertToSWT(BufferedImage bufferedImage) { if (bufferedImage.getColorModel() instanceof DirectColorModel) { /* DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel(); PaletteData palette = new PaletteData( colorModel.getRedMask(), colorModel.getGreenMask(), colorModel.getBlueMask()); ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette); WritableRaster raster = bufferedImage.getRaster(); int[] pixelArray = new int[3]; for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { raster.getPixel(x, y, pixelArray); int pixel = palette.getPixel(new RGB(pixelArray[0], pixelArray[1], pixelArray[2])); data.setPixel(x, y, pixel); } } */ DirectColorModel colorModel = (DirectColorModel)bufferedImage.getColorModel(); PaletteData palette = new PaletteData( colorModel.getRedMask(), colorModel.getGreenMask(), colorModel.getBlueMask()); ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette); for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { int rgb = bufferedImage.getRGB(x, y); int pixel = palette.getPixel(new RGB((rgb >> 16) & 0xFF, (rgb >> 8) & 0xFF, rgb & 0xFF)); data.setPixel(x, y, pixel); if (colorModel.hasAlpha()) { data.setAlpha(x, y, (rgb >> 24) & 0xFF); } } } return data; } else if (bufferedImage.getColorModel() instanceof IndexColorModel) { IndexColorModel colorModel = (IndexColorModel)bufferedImage.getColorModel(); int size = colorModel.getMapSize(); byte[] reds = new byte[size]; byte[] greens = new byte[size]; byte[] blues = new byte[size]; colorModel.getReds(reds); colorModel.getGreens(greens); colorModel.getBlues(blues); RGB[] rgbs = new RGB[size]; for (int i = 0; i < rgbs.length; i++) { rgbs[i] = new RGB(reds[i] & 0xFF, greens[i] & 0xFF, blues[i] & 0xFF); } PaletteData palette = new PaletteData(rgbs); ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette); data.transparentPixel = colorModel.getTransparentPixel(); WritableRaster raster = bufferedImage.getRaster(); int[] pixelArray = new int[1]; for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { raster.getPixel(x, y, pixelArray); data.setPixel(x, y, pixelArray[0]); } } return data; } else if (bufferedImage.getColorModel() instanceof ComponentColorModel) { ComponentColorModel colorModel = (ComponentColorModel)bufferedImage.getColorModel(); //ASSUMES: 3 BYTE BGR IMAGE TYPE PaletteData palette = new PaletteData(0x0000FF, 0x00FF00,0xFF0000); ImageData data = new ImageData(bufferedImage.getWidth(), bufferedImage.getHeight(), colorModel.getPixelSize(), palette); //This is valid because we are using a 3-byte Data model with no transparent pixels data.transparentPixel = -1; WritableRaster raster = bufferedImage.getRaster(); int[] pixelArray = new int[3]; for (int y = 0; y < data.height; y++) { for (int x = 0; x < data.width; x++) { raster.getPixel(x, y, pixelArray); int pixel = palette.getPixel(new RGB(pixelArray[0], pixelArray[1], pixelArray[2])); data.setPixel(x, y, pixel); } } return data; } return null; }