How to create TYPE_INT_RGB BufferedImage from memory pixels

Question

Hello
Using this code, I can make BufferedImage out of memory pixel array, but it is of TYPE_INT_ARGB type and I want it to be TYPE_INT_RGB
How can I do it ?
here's my code:
int [] pixels=new int[width*height];
Databuffer dataBuffer1 = new DataBufferInt (pixels, width*height);
int [] masks = {0xFF0000, 0xFF00, 0xFF, 0xFF000000};
SampleModel sampleModel = new SinglePixelPackedSampleModel(DataBuffer.TYPE_INT, width, height, masks);
WritableRaster writableRaster1 = Raster.createWritableRaster (sampleModel, dataBuffer1, null);
ColorModel color_model = ColorModel.getRGBdefault ();
BufferedImage  bufImage1=new BufferedImage (color_model,writableRaster1,false,null);

Answer 1

Question 1
To create a multipage tiff you use the method TIFFEncodeParam#setExtraImages. The method takes an iterator. I'm not sure if there is a built in way to append pages to an already existing file, but in theory you can read from the already existing file as needed (when iterator#next is called) and write to a temporary file, before replacing the existing file with the temporary one. So you'll still have to read the existing file, but you don't have to keep all the images in memory.
If you switch to core java's ImageWriter/ImageReader api and get [JAI-Imageio|https://jai-imageio.dev.java.net/binary-builds.html] (which has a TIFF ImageWriter plugin) then you can insert images into an already existing file. Presumably the TIFF ImageWriter appends directly to the file.
Question 2
The only thing special about a BufferedImage is that it has exactly one raster at (0,0) and it's guaranteed to have a color model. RenderedImages may have more than one raster and are not guaranteed to have a color model. But if your RenderedImage does have a color model, then you get rgb data from it the same way a BufferedImage does,
colorModel.getRGB(raster.getDataElements(x, y, null));There are other ways, but this is the most generic.