Convert and display image from byte array - java

I'm making a program, which gets data about an image in byte array from a server. I'm converting this data into 24bit BMP format (whether its jpeg, png, bmp or 8-24-32bpp). First, I'm saving it to my HD, and then I'm loading it into a JLabel's Icon. Works perfectly, though there are some cases in which I get the following exception:
java.io.EOFException at
javax.imageio.stream.ImageInputStreamImpl.readFully(ImageInputStreamImpl.java:353) at
com.sun.imageio.plugins.bmp.BMPImageReader.read24Bit(BMPImageReader.java:1188) at
com.sun.imageio.plugins.bmp.BMPImageReader.read(BMPImageReader.java:843) at
javax.imageio.ImageIO.read(ImageIO.java:1448) at
javax.imageio.ImageIO.read(ImageIO.java:1308)
For this line (the second)
File imgFile = new File("d:/image.bmp");
BufferedImage image = ImageIO.read(imgFile);
In these cases:
the image does not load into the JLabel, but it can be found on my HD
the conversion is not proper, because something "slips"
the picture is like when you use italics in a word document
First, i thought maybe the bpp is the problem, then i thought that maybe the pictures are too large, but i have cases it works and cases it doesn't for both suggestions. I'm a little stuck here, and would be glad for ideas.

the picture is like .. when You use italics in a word document
Think I finally got what this bullet item meant now.. ;-)
Speculative answer, but here goes:
If the image you write looks "skewed", it's probably due to missing padding for each column as the BMP format specifies (or incorrect width field in the BMP header). I assume then, that the images you get EOF exceptions for, is where the width is not a multiple of 4.
Try to write the BMPs using ImageIO to see if that helps:
private static BufferedImage createRGBImage(byte[] bytes, int width, int height) {
DataBufferByte buffer = new DataBufferByte(bytes, bytes.length);
ColorModel cm = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), new int[]{8, 8, 8}, false, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
return new BufferedImage(cm, Raster.createInterleavedRaster(buffer, width, height, width * 3, 3, new int[]{0, 1, 2}, null), false, null);
}
...
byte[] bytes = ...; // Your image bytes
OutputStream stream = ...; // Your output
BufferedImage image = createRGBImage(bytes, width, height);
try {
ImageIO.write(image, "BMP", stream);
}
finally {
stream.close();
}

Call it by class name, liek ClassName.byteArrayToImage(byte):
public static BufferedImage byteArrayToImage(byte[] bytes){
BufferedImage bufferedImage=null;
try {
InputStream inputStream = new ByteArrayInputStream(bytes);
bufferedImage = ImageIO.read(inputStream);
} catch (IOException ex) {
System.out.println(ex.getMessage());
}
return bufferedImage;
}

You can use this code to convert the output image to a byte Array
Blob b = rs.getBlob(2);
byte barr[] = new byte[(int)b.length()]; //create empty array
barr = b.getBytes(1,(int)b.length());
FileOutputStream fout = new FileOutputStream("D:\\sonoo.jpg");
fout.write(barr);

Related

BufferedImageOp Kernel Convolution not doing anything

I am attempting to perform a basic kernel convolution pass on an image using the BufferedImageOp package in java.awt.image. This is the code I have:
BufferedImage img = null;
File f = null;
//read image
try {
f = new File("keys.JPG");
img = ImageIO.read(f);
} catch (IOException e) {
System.out.println(e);
}
float[] gaussian = {
1/16f, 1/8f, 1/16f,
1/8f, 1/4f, 1/8f,
1/16f, 1/8f, 1/16f,
};
BufferedImageOp op = new ConvolveOp(new Kernel(3, 3, gaussian));
BufferedImage dest = op.filter(img, null);
File outputfile = new File("image.jpg");
ImageIO.write(dest, "jpg", outputfile);
My code attempts to load the image keys.JPG and then convolve this image with the Gaussian blur kernel and save the image to the file image.jpg. When I run the code, it processes for a bit then terminates and saves the image successfully but when I compare the original and the new images, they are identical.
Looking online at some code examples, my code should work. Am I missing something?
Thanks
As #haraldK mentioned, my image was too large to notice a difference. The code works as expected.

getting a bufferedImage from a bytearray

I am trying to get back a bufferedImage from array of bytes, but I am getting an error saying bufferedimage is null. I actually tried several ways, everything ended up in the same way. Here goes my code:
1)
byte[] arr = Base64.decode(base64String);
BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
2)
InputStream in = new ByteArrayInputStream(arr);
BufferedImage bImageFromConvert = ImageIO.read(in);
I am pretty sure my byte array contains data and I think ImageIO.read() is where my code goes wrong.
The error is in your BufferedImage to Base64 encode method as you have posted in the comments.
You are never writing the BufferedImage to the ByteArrayOutputStream. Therefore the Base64 string is empty, and reading the empty string produces a null BufferedImage.
You should use this code to encode your image:
BufferedImage originalImage = ImageIO.read(new File("G:\\a.jpg"));
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write( originalImage, "jpg", baos );
String base64String=Base64.encode(baos.toByteArray());
To decode the image use this code:
byte[] arr = Base64.decode(base64String);
BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
System.out.println(bImageFromConvert.getWidth());
Try this code.Maybe it works. It worked for me.
byte[] aByteArray = {};
int width = ;
int height = ;
DataBuffer buffer = new DataBufferByte(aByteArray, aByteArray.length);
WritableRaster raster = Raster.createInterleavedRaster(buffer, width, height, 3 * width, 3, new int[] {0, 1, 2}, (Point)null);
ColorModel cm = new ComponentColorModel(ColorModel.getRGBdefault().getColorSpace(), false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
BufferedImage image = new BufferedImage(cm, raster, true, null);
Just add the byte, width and height to code and customize it.

Change in color while using ImageIO.read()

I am trying to read images from external directory and for that I am using
bufferedImage image=ImageIO.read(new File(imagefile));
jlabel.seticon(new imageicon(image));
and getting a drastic change in colors. I tried many other things like:
bufferedImage image=ImageIO.read(new File(imagefile));
bufferedImage img=new bufferedImage(image.getWidth(),image.getHeight(),bufferedImage.TYPE_INT_RGB);
and I tried:
img.setData(image.getData();
jlabel.seticon(new imageicon(image));
and I tried:
Iterator readers = ImageIO.getImageReadersByFormatName("JPEG");
ImageReader reader = null;
while(readers.hasNext()) {
reader = (ImageReader)readers.next();
if(reader.canReadRaster()) {
break;
}
}
ImageInputStream input = ImageIO.createImageInputStream(f);
reader.setInput(input);
Raster raster = reader.readRaster(0, null);
BufferedImage bi = new BufferedImage(raster.getWidth(), raster.getHeight(),
BufferedImage.TYPE_4BYTE_ABGR);
bi.getRaster().setRect(raster);
but result are still same
http://i.stack.imgur.com/jNVm0.jpg
Here is an example of the issue:
The minimal code for viewing is:
bufferedImage image=ImageIO.read(new File(imagefile));
jlabel.seticon(new imageicon(image));
lbitem.setIcon(im);
and for storing
File f = new File(s);
long size=f.length();
FileInputStream fis1=new FileInputStream(f);
FileOutputStream fos2=new FileOutputStream("src/image/"+tfpn.getText()+".jpg");
byte b[]=new byte[1000];
int r=0;
long count=0;
while(true)
{
r=fis1.read(b,0,1000);
fos2.write(b,0,1000);
count = count+r;
if(count==size)
break;
System.out.println(count);
}
What could be causing the bad colors?
This problem is cause by a mismatch between reading/writing (creating/using) an image
that contains alpha (transparency) but you are expecting it to contain no alpha (or the inverse).
For example, if your image is BufferedImage.TYPE_4BYTE_ABGR and you output it
to a file type that does not support alpha (transparency) , or you writer does not
support alpha, it will look like your sample after reading and displaying it.
Use type PNG (supports alpha channel) not JPG (does not support alpha channel)

JAVA : How to create .PNG image from a byte[]?

I have seen some code source, but I do not understand...
I use Java 7
Please, how to convert a RGB (Red,Green,Blue) Byte Array (or something similar) to a .PNG file format ?
Example from an array that could represent "a RGB pixel" :
byte[] aByteArray={0xa,0x2,0xf};
Important Aspect :
I try to generate a .PNG file only from a byte[] "not from a previous existing file"
is it possible with an existing API? ;)
Here my first code :
byte[] aByteArray={0xa,0x2,0xf};
ByteArrayInputStream bais = new ByteArrayInputStream(aByteArray);
File outputfile = new File("image.png");
ImageIO.write(bais, "png", outputfile);
....Error : No suitable Method Found
Here the other version modified from Jeremy but look similar :
byte[] aByteArray={0xa,0x2,0xf};
ByteArrayInputStream bais = new ByteArrayInputStream(aByteArray);
final BufferedImage bufferedImage = ImageIO.read(newByteArrayInputStream(aByteArray));
ImageIO.write(bufferedImage, "png", new File("image.png"));
....multiple Errors : image == null! ...... Sure ? Note : I do not search to use a source file
The Image I/O API deals with images, so you need to make an image from your byte array first before you write it out.
byte[] aByteArray = {0xa,0x2,0xf,(byte)0xff,(byte)0xff,(byte)0xff};
int width = 1;
int height = 2;
DataBuffer buffer = new DataBufferByte(aByteArray, aByteArray.length);
//3 bytes per pixel: red, green, blue
WritableRaster raster = Raster.createInterleavedRaster(buffer, width, height, 3 * width, 3, new int[] {0, 1, 2}, (Point)null);
ColorModel cm = new ComponentColorModel(ColorModel.getRGBdefault().getColorSpace(), false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
BufferedImage image = new BufferedImage(cm, raster, true, null);
ImageIO.write(image, "png", new File("image.png"));
This assumes the byte array has three bytes per pixel (red, green then blue) and the range of values is 0-255.

How to make custom Tiles in android google maps

Android's Google Maps api v2 provides a TileOverlay to which TileProviders can be added. A TileProvider will generate a Tile object given the lat, long, and depth. In order to make a tile, one must give it width (easy), height (easy), and an image represented as a byte array (confusing me). If I wanted to 'draw' a simple object and then turn it into a byte array, how would I do this?
For instance I am looking for something that looks like
Canvas canvas = new canvas();
...
canvas.drawRect(); //Or something like this (just an example)
...
byte[] bytes = canvas.SomeConversionFunctionOrProcessThatIDontKnow();
return new Tile(1,1,bytes);
public byte[] getByteArray (String image) throws IOException {
File yourImg = new File(image);
BufferedImage bufferedImage = ImageIO.read(yourImg);
WritableRaster wRaster = bufferedImage .getRaster();
DataBufferByte data = (DataBufferByte) wRaster.getDataBuffer();
return data.getData();
}
This should do the trick ; )
Tile#data should be compressed image data in one of the supported image formats. In other words, the raw contents of an image file. If you already have a decoded Bitmap, use Bitmap#compress(...) to write it to a ByteArrayOutputStream, then get the byte[] from that.
Bitmap bitmap = Bitmap.createBitmap(TILE_DIMENSION, TILE_DIMENSION,Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
......
//draw something
......
Tile tile = convertBitmap(bitmap);
bitmap.recycle();
return tile;
}
private Tile convertBitmap(Bitmap bitmap){
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] bitmapData = stream.toByteArray();
return new Tile(TILE_DIMENSION, TILE_DIMENSION, bitmapData);
}

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