How do I specify 16bit R5G6B5 pixels when creating a BufferedImage?

Question

Hello All,
I'm trying to load raster data from an image file and it may contain different bit depths. I'm loading this data into a BufferedImage using the constructor
BufferedImage(ColorModel cm, WritableRaster raster, boolean isRasterPremultiplied, Hashtable<?,?> properties)
I'm trying to figure out how to specify the exact way the pixels are stored, but I'm having a really hard time. It seems that I would want to put this information in the ColorModel, but I can't find anything to specify that. The WritableRaster is another place I looked, but when I create that, it also doesn't ask for (or I don't know how to provide) the specific color info. I have a file that stores it's pixel data in 16 bits, but the colors are separated out by Red (5bits) Green(6bits) Blue(5bits). I have the hex color masks for the color, but I don't know how to use them without first creating a BufferedImage, then using a PixelGrabber or other such process for editing the pixels after the fact. I'd like to be able to specify the the info when I create the image. Can anybody help me?
Thank you!

Answer 1

Quasi_Stomach wrote:
If I use the SinglePixelPackedSampleModel, I'm required to provide a scanlineStride and bandMask array. Do you know what these mean?I think you're referring to this constructor:
public SinglePixelPackedSampleModel(int dataType, int w, int h, int scanlineStride, int[] bitMasks)Ultimately, the data is going to be stored in a one dimensional array, say a short[]. The SampleModel knows how to access the data elements for the pixel in row r column c, for example.
Suppose I have a short[] where each short represents a pixel packed as 565_RGB. Bit masks are needed to extract the red, green and blue components from a short. These masks are:
int[] bitMasks = {0xF800, 0x7E0, 0x1F}; Write those out in binary and you'll see.
Second, an image is two-dimensional but a DataBuffer is one-dimensional -- basically a short[] in our case. How is the image folded in? Row by row. If you ran through the data in the short[] you would see row 0 of the image, then row 1, row 2, etc... But sometimes there's padding in there. It may be advantageous (because of video hardware) for the image width to be a power of 2: 2, 4, 8, 16, 32... and if the width isn't there may be padding (zeroes) in the short[] that guarantee that each row's data starts at an offset that is a multiple of a power of two. For example, you may have an image with width 200 that's padded out to 256, and the rows start at offsets [0], [256], [512], ...
This larger width, 256, is the scanlineStride. Chances are, if you don't know about a specific scanlineStride, it's going to be the same as the width.
Edit: All this being said, I can't remember the last time I needed to directly create or manipulate a SampleModel. Are you sure you need to go this low level? Perhaps you need to step back and describe the big picture. There may be another approach that's much easier to do what ever it is you are trying to do.