Develop Reference

ImageIO write specific tiff

I try to convert (with ImageIO ->
https://github.com/haraldk/TwelveMonkeys) a image into a specific tiff, like imagemagick does. I have a input image and want to write a specific tiff with following:
PLANAR_CONFIGURATION = 1
SAMPLES_PER_PIXEL = 1
BITS_PER_SAMPLE = 1
Y_RESOLUTION = 196
X_RESOLUTION = 204
IMAGE_WIDTH = 1728
Any idea how to render the inputstream? Currently the image is just converted into tiff.
BufferedImage image = ImageIO.read(inputstream)
ImageIO.write( image, "tiff", outputstream );

As #fmw42 says, making the image 1-bit you have do yourself. The TIFFImageWriter plugin will write the image it is passed as-is. Fortunately, this is not difficult to do.
Here's an easy (but not very sophisticated) way to convert the image to binary:
private static BufferedImage toBinary(BufferedImage original) {
if (original.getType() == BufferedImage.TYPE_BYTE_BINARY) {
return original;
}
// Quick and unsophisticated way to convert to B/W binary, using default dither and threshold (fixed, 50% I think)
BufferedImage image = new BufferedImage(original.getWidth(), original.getHeight(), BufferedImage.TYPE_BYTE_BINARY);
Graphics2D g = image.createGraphics();
try {
g.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
g.setComposite(AlphaComposite.Src);
g.drawImage(original, 0, 0, null);
}
finally {
g.dispose();
}
return image;
}
I'll leave it as an exercise to write more advanced solutions, using adaptive thresholding, error-diffusion dithering etc.
Now you can use the following code, and you're nearly there:
public static void main(String[] args) throws IOException {
BufferedImage original = ImageIO.read(new File(args[0]));
ImageIO.write(toBinary(original), "TIFF", new File("out.tif"));
}
Unfortunately, this will not set the X and Y Resolution tags. If you need that as well, you have to dig a little deeper into the ImageIO API, and figure out how to use the metadata to control the output. Note that only some of the values in the metadata may be set in this way. Other values will be computed from the image data passed in, and some may be filled in with default values by the writer.
You can use the following code (the toBinary method is the same as above):
public static void main(String[] args) throws IOException {
BufferedImage original = ImageIO.read(new File(args[0]));
BufferedImage image = toBinary(original);
ImageWriter writer = ImageIO.getImageWritersByFormatName("TIFF").next();
try (ImageOutputStream stream = ImageIO.createImageOutputStream(new File("out.tif"))) {
// You may use the param to control compression
ImageWriteParam param = writer.getDefaultWriteParam();
IIOMetadata metadata = writer.getDefaultImageMetadata(ImageTypeSpecifier.createFromRenderedImage(image), param);
Node root = metadata.getAsTree("com_sun_media_imageio_plugins_tiff_image_1.0"); // "javax_imageio_tiff_image_1.0" will work in later versions
Node ifd = root.getFirstChild();
// Add X and Y resolution tags
ifd.appendChild(createResTag("282", "XResolution", "204/1"));
ifd.appendChild(createResTag("283", "YResolution", "196/1"));
// Merge changes back to metadata
metadata.mergeTree("com_sun_media_imageio_plugins_tiff_image_1.0", root);
// Write full image, with metadata
writer.setOutput(stream);
writer.write(null, new IIOImage(image, null, metadata), param);
}
finally {
writer.dispose();
}
}
private static IIOMetadataNode createResTag(String tagNumber, String tagName, String tagValue) {
IIOMetadataNode res = new IIOMetadataNode("TIFFField");
res.setAttribute("number", tagNumber);
res.setAttribute("name", tagName); // Tag name is optional
IIOMetadataNode value = new IIOMetadataNode("TIFFRational");
value.setAttribute("value", tagValue);
IIOMetadataNode rationals = new IIOMetadataNode("TIFFRationals");
rationals.appendChild(value);
res.appendChild(rationals);
return res;
}
PS: The TwelveMonkeys TIFF plugin currently don't write PlanarConfiguration: 1, as this is the default value, and there's no way to force it. But it should not matter, as all compliant TIFF software must use the default value in this case.

How to save indexed color PNG in java

How to save image in java as java.awt.image.IndexColorModel PNG? I'm loading indexed color png with ImageIO, manipulate it with Catalino library which unfortunately converts the color space to java.awt.image.DirectColorModel.
Now I want to save the result in the exactly same format as the original image. I tried the following snippet of code.
private static void testIndexedColor() throws IOException {
FastBitmap input = new FastBitmap("test.png");
BufferedImage bi = new BufferedImage(input.getWidth(), input.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
bi.getGraphics().drawImage(input.toBufferedImage(), 0, 0, null);
ImageIO.write(bi, "PNG", new File("test_result.png"));
}
But in the result weird light gray pixel artifacts appeared in the white background, and PPI decreased . How to correctly convert back to indexed color mode without quality loss and distortion?

Assuming I'm correct about the Catalano framework, you should be able to re-write your methods as this:
private static void testIndexedColor() throws IOException {
BufferedImage bi = ImageIO.read(new File("test.png"));
FastBitmap input = new FastBitmap(bi);
Graphics2D g = bi.createGraphics();
try {
g.drawImage(input.toBufferedImage(), 0, 0, null);
}
finally {
g.dispose(); // Good practice ;-)
}
ImageIO.write(bi, "PNG", new File("test_result.png"));
}
At least you should get away with the fixed palette and the artifacts.
However, this will likely still modify the PPI (but this won't affect the pixels). And even in some cases the image might be written back as a non-palette PNG.
Update: It seems the PNGImageWriter (through the PNGMetadata) actually re-writes an IndexColorModel containing a perfect grayscale, to a grayscale PNG by default. This is normally a good idea, as you reduce file size by not writing the PLTE chunk. You should be able to get around this, by passing the metadata from the original, along with the image pixel data, to instruct the writer to keep the IndexColorModel (ie. write PLTE chunk):
private static void testIndexedColor() throws IOException {
File in = new File("test.png");
File out new File("test_result.png");
try (ImageInputStream input = ImageIO.createImageInputStream(in);
ImageOutputStream output = ImageIO.createImageOutputStream(out)) {
ImageReader reader = ImageIO.getImageReaders(input).next(); // Will fail if no reader
reader.setInput(input);
ImageWriter writer = ImageIO.getImageWriter(reader); // Will obtain a writer that understands the metadata from the reader
writer.setOutput(output); // Will fail if no writer
// Now, the important part, we'll read the pixel AND metadata all in one go
IIOImage image = reader.readAll(0, null); // PNGs only have a single image, so index 0 is safe
// You can now access and modify the image data using:
BufferedImage bi = (BufferedImage) image.getRenderedImage();
FastBitmap fb = new FastBitmap(bi);
// ...do stuff...
Graphics2D g = bi.createGraphics();
try {
g.drawImage(fb.toBufferedImage(), 0, 0, null);
}
finally {
g.dispose();
}
// Write pixel and metadata back
writer.write(null, image, writer.getDefaultWriteParam());
}
}
This should (as a bonus) also keep your PPI as-is.
PS: For production code, you also want to dispose() of the reader and writer above, but I left it out to keep focus and avoid further discussion on try/finally. ;-)

ImageIO saves back to original size

I've been searching for some solutions from the internet yet I still haven't found an answer to my problem.
I've been working or doing a program that would get an image file from my PC then will be edited using Java Graphics to add some text/object/etc. After that, Java ImageIO will save the newly modified image.
So far, I was able to do it nicely but I got a problem about the size of the image. The original image and the modified image didn't have the same size.
The original is a 2x3inches-image while the modified one which supposedly have 2x3inches too sadly got 8x14inches. So, it has gone BIGGER than the original one.
What is the solution/code that would give me an output of 2x3inches-image which will still have a 'nice quality'?
UPDATE:
So, here's the code I used.
public Picture(String filename) {
try {
File file = new File("originalpic.jpg");
image = ImageIO.read(file);
width = image.getWidth();
}
catch (IOException e) {
throw new RuntimeException("Could not open file: " + filename);
}
}
private void write(int id) {
try {
ImageIO.write(image, "jpg", new File("newpic.jpg"));
} catch (IOException e) {
e.printStackTrace();
}
}
2nd UPDATE:
I now know what's the problem of the new image. As I check it from Photoshop, It has a different image resolution compared to the original one. The original has a 300 pixels/inch while the new image has a 72 pixels/inch resolution.
How will I be able to change the resolution using Java?

To set the image resolution (of the JFIF segment), you can probably use the IIOMetatada for JPEG.
Something along the lines of:
public class MetadataTest {
public static void main(String[] args) throws IOException {
BufferedImage image = new BufferedImage(100, 100, BufferedImage.TYPE_3BYTE_BGR);
ImageWriter writer = ImageIO.getImageWritersByFormatName("jpeg").next();
writer.setOutput(ImageIO.createImageOutputStream(new File("foo.jpg")));
ImageWriteParam param = writer.getDefaultWriteParam();
IIOMetadata metadata = writer.getDefaultImageMetadata(ImageTypeSpecifier.createFromRenderedImage(image), param);
IIOMetadataNode root = (IIOMetadataNode) metadata.getAsTree(metadata.getNativeMetadataFormatName());
IIOMetadataNode jfif = (IIOMetadataNode) root.getElementsByTagName("app0JFIF").item(0);
jfif.setAttribute("resUnits", "1");
jfif.setAttribute("Xdensity", "300");
jfif.setAttribute("Ydensity", "300");
metadata.mergeTree(metadata.getNativeMetadataFormatName(), root);
writer.write(null, new IIOImage(image, null, metadata), param);
}
}
Note: this code should not be used verbatim, but adding iteration, error handling, stream closing etc, clutters the example too much.
See JPEG Image Metadata DTD for documentation on the metadata format, and what options you can control.

How to save a BufferedImage as a File

I am using the imgscalr Java library to resize an image .
The result of a resize() method call is a BufferedImage object. I now want to save this as a file (usually .jpg).
How can I do that? I want to go from BufferedImage -> File but perhaps this is not the correct approach?

File outputfile = new File("image.jpg");
ImageIO.write(bufferedImage, "jpg", outputfile);

The answer lies within the Java Documentation's Tutorial for Writing/Saving an Image.
The Image I/O class provides the following method for saving an image:
static boolean ImageIO.write(RenderedImage im, String formatName, File output) throws IOException
The tutorial explains that
The BufferedImage class implements the RenderedImage interface.
so it's able to be used in the method.
For example,
try {
BufferedImage bi = getMyImage(); // retrieve image
File outputfile = new File("saved.png");
ImageIO.write(bi, "png", outputfile);
} catch (IOException e) {
// handle exception
}
It's important to surround the write call with a try block because, as per the API, the method throws an IOException "if an error occurs during writing"
Also explained are the method's objective, parameters, returns, and throws, in more detail:
Writes an image using an arbitrary ImageWriter that supports the given format to a File. If there is already a File present, its contents are discarded.
Parameters:
im - a RenderedImage to be written.
formatName - a String containg the informal name of the format.
output - a File to be written to.
Returns:
false if no appropriate writer is found.
Throws:
IllegalArgumentException - if any parameter is null.
IOException - if an error occurs during writing.
However, formatName may still seem rather vague and ambiguous; the tutorial clears it up a bit:
The ImageIO.write method calls the code that implements PNG writing a “PNG writer plug-in”. The term plug-in is used since Image I/O is extensible and can support a wide range of formats.
But the following standard image format plugins : JPEG, PNG, GIF, BMP and WBMP are always be present.
For most applications it is sufficient to use one of these standard plugins. They have the advantage of being readily available.
There are, however, additional formats you can use:
The Image I/O class provides a way to plug in support for additional formats which can be used, and many such plug-ins exist. If you are interested in what file formats are available to load or save in your system, you may use the getReaderFormatNames and getWriterFormatNames methods of the ImageIO class. These methods return an array of strings listing all of the formats supported in this JRE.
String writerNames[] = ImageIO.getWriterFormatNames();
The returned array of names will include any additional plug-ins that are installed and any of these names may be used as a format name to select an image writer.
For a full and practical example, one can refer to Oracle's SaveImage.java example.

You can save a BufferedImage object using write method of the javax.imageio.ImageIO class. The signature of the method is like this:
public static boolean write(RenderedImage im, String formatName, File output) throws IOException
Here im is the RenderedImage to be written, formatName is the String containing the informal name of the format (e.g. png) and output is the file object to be written to. An example usage of the method for PNG file format is shown below:
ImageIO.write(image, "png", file);

Create and save a java.awt.image.bufferedImage to file:
import java.io.*;
import java.awt.image.*;
import javax.imageio.*;
public class Main{
public static void main(String args[]){
try{
BufferedImage img = new BufferedImage(
500, 500, BufferedImage.TYPE_INT_RGB );
File f = new File("MyFile.png");
int r = 5;
int g = 25;
int b = 255;
int col = (r << 16) | (g << 8) | b;
for(int x = 0; x < 500; x++){
for(int y = 20; y < 300; y++){
img.setRGB(x, y, col);
}
}
ImageIO.write(img, "PNG", f);
}
catch(Exception e){
e.printStackTrace();
}
}
}
Notes:
Creates a file called MyFile.png.
Image is 500 by 500 pixels.
Overwrites the existing file.
The color of the image is black with a blue stripe across the top.

Download and add imgscalr-lib-x.x.jar and imgscalr-lib-x.x-javadoc.jar to your Projects Libraries.
In your code:
import static org.imgscalr.Scalr.*;
public static BufferedImage resizeBufferedImage(BufferedImage image, Scalr.Method scalrMethod, Scalr.Mode scalrMode, int width, int height) {
BufferedImage bi = image;
bi = resize( image, scalrMethod, scalrMode, width, height);
return bi;
}
// Save image:
ImageIO.write(Scalr.resize(etotBImage, 150), "jpg", new File(myDir));

As a one liner:
ImageIO.write(Scalr.resize(ImageIO.read(...), 150));

Merge small images into one without allocating full image in memory

I've to make a parallel image processing script in java, the idea is to divide the images into tiles of any size, process them, and reassemble the final image.
For now i've created a function:
public static BufferedImage readImg (String path, int startx, int starty, int w, int h)
that returns the region of an image as BufferedImage, then i'll process it and i want to place that region in the correct position of the final image.
So i've tried to make a function writeImg that uses replacePixels method to write just in the correct position without loading the whole image into memory:
public static void writeImg (String path, int startx, int starty, BufferedImage image){
File output = new File(path);
ImageOutputStream ios = null;
try {
ios = ImageIO.createImageOutputStream(output);
} catch (IOException e){
e.printStackTrace();
}
Iterator iter = ImageIO.getImageWritersByFormatName("JPEG");
ImageWriter writer = (ImageWriter)iter.next();
writer.setOutput(ios);
try{
if(writer.canReplacePixels(0)){
System.out.println("True");
}else{
System.out.println("False");
}
}catch (IOException e) {
e.printStackTrace();
}
ImageWriteParam param = writer.getDefaultWriteParam();
Point destinationOffset = new Point(startx,starty);
param.setDestinationOffset(destinationOffset);
try {
writer.replacePixels(image, param);
} catch (IOException e) {
e.printStackTrace();
}
}
The problem is that canReplacePixels is always set as false, and i've no idea what should i use to do that.
The images can be very big so it's impossible to load the whole image in memory as it will cause a OutOfMemory exception.

As long as you are fine with an 24 bit PNG file as output I have a working solution for you (under GPL license):
The class PngXxlWriter allows to write PNG files "line by line". That means that you can write an image of 10000x10000 (width * height) pixels in lines of e.g. 256 pixels (10000 * 256).
Usually this reduces the memory usage down to a level which is practically.
All required classes can be found here:
PngXxlWriter is the main class. By calling its method writeTileLine you can add a new line to the output image.
https://sourceforge.net/p/mobac/code/HEAD/tree/trunk/MOBAC/src/main/java/mobac/utilities/imageio/