I've been working towards grayscaling images in java for some time. I was using a colorConvertOp, but it seems after a load of images were put through the process, eventually the JVM would hang in a locked state in the op.
Now I've started using:
BufferedImage image = new BufferedImage(size, size, BufferedImage.TYPE_BYTE_GRAY);
Graphics g = image.getGraphics();
g.drawImage(img, 0, 0, null);
g.dispose();
However, I'm seeing a large spike in CPU, where it used to be under 20% and is now up to 120%. It also seems to be causing me memory leaks and eventually OOMs.
Is there an easier, quicker way to grayscale in java without using as much CPU/eliminates hanging from a JVM bug?
I wrote a java program to convert RGB image to GrayScaleImage. Hope this helps
public class GrayScale {
BufferedImage image;
int width;
int height;
public GrayScale() {
try {
File input = new File("input path of the image");
image = ImageIO.read(input);
width = image.getWidth();
height = image.getHeight();
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
Color c = new Color(image.getRGB(j, i));
int red = (int) (c.getRed() * 0.299);
int green = (int) (c.getGreen() * 0.587);
int blue = (int) (c.getBlue() * 0.114);
Color newColor = new Color(red + green + blue,
red + green + blue, red + green + blue);
image.setRGB(j, i, newColor.getRGB());
}
}
File ouptut = new File("output path of the image");
ImageIO.write(image, "jpg", ouptut);
} catch (Exception e) {
}
}
static public void main(String args[]) throws Exception {
GrayScale obj = new GrayScale();
}
}
Related
Is there some really simple and basic code for making preview for HDR images (like getting 2D BufferedImage output or something)?
I am using this HDR image.
I tried this (it uses TwelveMonkeys), but no success at all (it simply stuck/frozen at ImageReader reader = readers.next();)
I edited it a bit to suit my needs like this, testing where it got broken/stuck/frozen...and it always happen after TEST 1, that is TEST 2 is never reached, tho no IllegalArgumentException is thrown - if I remove the if() section, then TEST 3 is never reached (I am using NetBeansIDE v12.4, Win7 x64):
public BufferedImage hdrToBufferedImage(File hdrFile) throws IOException {
BufferedImage bi = null;
// Create input stream
// I WROTE DOWN THE STRING FOR THIS EXAMPLE, normally it is taken from the hdrFile
// HDR image size is 23.7MB if it matters at all?
ImageInputStream input = ImageIO.createImageInputStream(new File("Z:/HDR/spiaggia_di_mondello_4k.hdr"));
try {
// Get the reader
Iterator<ImageReader> readers = ImageIO.getImageReaders(input);
System.err.println("=====>>> TEST 1");
if (!readers.hasNext()) {
throw new IllegalArgumentException("No reader for: " + hdrFile);
}
System.err.println("=====>>> TEST 2");
ImageReader reader = readers.next();
System.err.println("=====>>> TEST 3");
try {
reader.setInput(input);
// Disable default tone mapping
HDRImageReadParam param = (HDRImageReadParam) reader.getDefaultReadParam();
param.setToneMapper(new NullToneMapper());
// Read the image, using settings from param
bi = reader.read(0, param);
} finally {
// Dispose reader in finally block to avoid memory leaks
reader.dispose();
}
} finally {
// Close stream in finally block to avoid resource leaks
input.close();
}
// Get float data
float[] rgb = ((DataBufferFloat) bi.getRaster().getDataBuffer()).getData();
// Convert the image to something easily displayable
BufferedImage converted = new ColorConvertOp(null).filter(bi, new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_INT_RGB));
return converted;
}
Well, if you don't mind occasional extreme halucinogenic oversaturation of some colors here and there (I was unable solving the issue - if anyone knows how to, please, feel free to update my code), you can try this (it is using JavaHDR) + I also added a bit of brightness and contrast to it as all HDR I tested looked too dark for the preview, so if you do not like that you can remove that part from the code:
public int rgbToInteger(int r, int g, int b) {
int rgb = r;
rgb = (rgb << 8) + g;
rgb = (rgb << 8) + b;
return rgb;
}
public BufferedImage hdrToBufferedImage(File hdrFile) throws IOException {
HDRImage hdr = HDREncoder.readHDR(hdrFile, true);
int width = hdr.getWidth();
int height = hdr.getHeight();
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
int r = (int) (hdr.getPixelValue(x, y, 0) * 255);
int g = (int) (hdr.getPixelValue(x, y, 1) * 255);
int b = (int) (hdr.getPixelValue(x, y, 2) * 255);
bi.setRGB(x, y, rgbToInteger(r, g, b));
}
}
//***** YOU CAN REMOVE THIS SMALL SECTION IF YOU FEEL THE IMAGE IS TOO BRIGHT FOR YOU
float brightness = 2f;
float contrast = 20f;
RescaleOp rescaleOp = new RescaleOp(brightness, contrast, null);
rescaleOp.filter(bi, bi);
//*****
return bi;
}
I can compile and run the code you posted (changing the path obviously) without problems on my two macOS machines, testing on all the LTS Java versions (8, 11 and 17). In addition, I run code similar to this as part of the CI/CD pipeline of my project that tests on Windows and Linux as well. I think there is something wrong with the setup in your IDE or Java on your computer. I am not able to reproduce the "freeze"-situation you describe...
Here is the output of running the program (I also printed the resulting BufferedImage for verification):
=====>>> TEST 1
=====>>> TEST 2
=====>>> TEST 3
image = BufferedImage#5a42bbf4: type = 1 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=0 IntegerInterleavedRaster: width = 1024 height = 512 #Bands = 3 xOff = 0 yOff = 0 dataOffset[0] 0
Running with the code as-is (with the NullToneMapper and no post-processing), the image looks like this, due to unnormalized values:
Running with the default/built-in tone mapper, or simply reading the image with ImageIO.read(hdrFile) as suggested in the comments, the image will look like this:
Finally, playing a bit with the code using a custom global tone mapper; param.setToneMapper(new DefaultToneMapper(0.75f)), I get a result like this:
After a long discussion with #HaraldK and his code addition, I am posting the final correct code for this problem, that is in fact mix of #qraqatit code updated a bit with the #HaraldK addition that corrects wrong color tone mapping, here it is:
public int rgbToInteger(int r, int g, int b) {
int rgb = r;
rgb = (rgb << 8) + g;
rgb = (rgb << 8) + b;
return rgb;
}
public BufferedImage hdrToBufferedImage(File hdrFile) throws IOException {
HDRImage hdr = HDREncoder.readHDR(hdrFile, true);
int width = hdr.getWidth();
int height = hdr.getHeight();
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
float colorToneCorrection = 0.75f;
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
float r = hdr.getPixelValue(x, y, 0);
int red = (int) ((r / (colorToneCorrection + r)) * 255);
float g = hdr.getPixelValue(x, y, 1);
int green = (int) ((g / (colorToneCorrection + g)) * 255);
float b = hdr.getPixelValue(x, y, 2);
int blue = (int) (int) ((b / (colorToneCorrection + b)) * 255);
bi.setRGB(x, y, rgbToInteger(red, green, blue));
}
}
//MAKE THE RESULTING IMAGE A BIT BRIGHTER
float brightness = 1.35f;
float contrast = 0f;
RescaleOp rescaleOp = new RescaleOp(brightness, contrast, null);
rescaleOp.filter(bi, bi);
return bi;
}
I have created a dialog in which a user can browse for an image and then see a preview of the image drawn on a canvas. The image is scaled so that its aspect ratio is maintained while fitting in the box. I used the method of resizing found in this answer, which involves converting an image from SWT to AWT, performing the resize, converting back from AWT to SWT, and finally drawing it on the canvas. Since this process is very costly in terms of time and processing power, I elect to skip the resizing step if the image is exactly the correct size, and thus does not need to be transformed in any way.
The issue comes up when dealing with images with alpha transparency. In some cases, images that have transparency that are converted first are drawn on the canvas with a black background. A copy of the same image that has been sized to the exact size of the canvas, and thus is not converted, has a white background.
However, this is also not always the case. Some images with transparent backgrounds will always show as white, whether they've been converted or not.
What causes an image with a transparent background to draw with one color over another in an SWT canvas? How does the AWT conversion affect it, and how can I cause it to become consistent if I so desire?
Here is the conversion code, taken in whole from another source:
public static BufferedImage convertToAWT (ImageData data) {
ColorModel colorModel = null;
PaletteData palette = data.palette;
if (palette.isDirect) {
colorModel = new DirectColorModel(data.depth, palette.redMask, palette.greenMask, palette.blueMask);
BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height),
false, null);
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++) {
int pixel = data.getPixel(x, y);
RGB rgb = palette.getRGB(pixel);
pixelArray[0] = rgb.red;
pixelArray[1] = rgb.green;
pixelArray[2] = rgb.blue;
raster.setPixels(x, y, 1, 1, pixelArray);
}
}
return bufferedImage;
}
else {
RGB[] rgbs = palette.getRGBs();
byte[] red = new byte[rgbs.length];
byte[] green = new byte[rgbs.length];
byte[] blue = new byte[rgbs.length];
for (int i = 0; i < rgbs.length; i++) {
RGB rgb = rgbs[i];
red[i] = (byte) rgb.red;
green[i] = (byte) rgb.green;
blue[i] = (byte) rgb.blue;
}
if (data.transparentPixel != -1) {
colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue, data.transparentPixel);
} else {
colorModel = new IndexColorModel(data.depth, rgbs.length, red, green, blue);
}
BufferedImage bufferedImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(data.width, data.height),
false, null);
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++) {
int pixel = data.getPixel(x, y);
pixelArray[0] = pixel;
raster.setPixel(x, y, pixelArray);
}
}
return bufferedImage;
}
}
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;
}
Ok, since I think I finally understand your requirements, I decided to post an answer. Let me make sure that I understood it correctly:
You want to show an Image in your app in some sort of Widget that can be resized. The image should resize with its parent and keep transparency working.
Instead of resizing the image and displaying it in a Label or some other Widget, you can use a Canvas and paint the image to the appropriate size using GC#drawImage(Image image, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY, int destWidth, int destHeight).
To use that function, you need the size of the Image, the size of the Canvas and the size of a correctly scaled (aspect ratio) version of the image.
Here is the code:
public static void main(String[] args)
{
Display display = Display.getDefault();
final Shell shell = new Shell(display);
shell.setLayout(new GridLayout(1, false));
/* Load the image and calculate size and ratio */
final Image image = new Image(display, "settings.png");
final Rectangle imageSize = image.getBounds();
final double imageRatio = 1.0 * imageSize.width / imageSize.height;
/* Define the canvas and set the background color */
final Canvas canvas = new Canvas(shell, SWT.BORDER);
canvas.setBackground(display.getSystemColor(SWT.COLOR_DARK_GRAY));
canvas.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
canvas.addListener(SWT.Paint, new Listener()
{
#Override
public void handleEvent(Event e)
{
Rectangle canvasSize = canvas.getBounds();
double canvasRatio = 1.0 * canvasSize.width / canvasSize.height;
int newHeight;
int newWidth;
/* Determine scaled height and width of the image */
if (canvasRatio > imageRatio)
{
newWidth = (int) (imageSize.width * (1.0 * canvasSize.height / imageSize.height));
newHeight = (int) (canvasSize.height);
}
else
{
newWidth = (int) (canvasSize.width);
newHeight = (int) (imageSize.height * (1.0 * canvasSize.width / imageSize.width));
}
/* Compute position such that the image is centered in the canvas */
int top = (int) ((canvasSize.height - newHeight) / 2.0);
int left = (int) ((canvasSize.width - newWidth) / 2.0);
/* Draw the image */
e.gc.drawImage(image, 0, 0, imageSize.width, imageSize.height, left, top, newWidth, newHeight);
}
});
shell.pack();
shell.open();
while (!shell.isDisposed())
{
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
/* DISPOSE THE IMAGE !!! */
image.dispose();
}
And this is what it looks like after starting:
and after resizing:
Note: I didn't have time to test it on Windows, but I'm fairly confident that it works.
It works on Windows as well!
EDIT:
Add these lines to enable antialiasing:
e.gc.setAntialias(SWT.ON);
e.gc.setAdvanced(true);
It's a bit late for an answer now, but as I've just had a similar experience and issues, I thought my findings might help others.
The original problem is with the supplied code that does the SWT->AWT and AWT->SWT conversions. When using a direct palette, transparency (alpha) is not catered for at all, but it is for an indexed palette, and that's why some images work and some do not.
It's relatively simple to fix that code to cope with transparency, but there are better solutions that do not need to got via AWT to get a resized image.
If you don't care about anti-aliasing (smoothness) of the converted image then a simple solution is:
Image newImage = new Image(image.getDevice(),
image.getImageData().scaledTo(newWidth, newHeight));
If you do care about smoothness then the solution is almost as simple:
Image newImage = new Image(image.getDevice(), newWidth, newHeight);
GC gc = new GC(newImage);
gc.setAdvanced(true);
gc.setAntialias(SWT.ON);
gc.drawImage(image, 0, 0, origWidth, origHeight, 0, 0, newWidth, newHeight);
gc.dispose();
I'm attempting to take a picture as input, then manipulate said picture (I specifically want to make it greyscale) and then output the new image. This is a snippet of the code that I'm editing in order to do so but I'm getting stuck. Any ideas of what I can change/do next. Greatly appreciated!
public boolean recieveFrame (Image frame) {
int width = frame.width();
int height = frame.height();
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j++) {
Color c1 = frame.get(i, j);
double greyScale = (double) ((Color.red *.3) + (Color.green *.59) + (Color.blue * .11));
Color newGrey = Color.greyScale(greyScale);
frame.set(i, j, newGrey);
}
}
boolean shouldStop = displayImage(frame);
return shouldStop;
}
I'm going to try to stick as close as possible to what you already have. So, I'll assume that you are looking for how to do pixel-level processing on an Image, rather than just looking for a technique that happens to work for converting to greyscale.
The first step is that you need the image to be a BufferedImage. This is what you get by default from ImageIO, but if you have some other type of image, you can create a BufferedImage and paint the other image into it first:
BufferedImage buffer = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
Graphics2D g = buffer.createGraphics();
g.drawImage(image, 0, 0);
g.dispose()
Then, you can operate on the pixels like this:
public void makeGrey(BufferedImage image) {
for(int x = 0; x < image.getWidth(); ++x) {
for(int y = 0; y < image.getHeight(); ++y) {
Color c1 = new Color(image.getRGB(x, y));
int grey = (int)(c1.getRed() * 0.3
+ c1.getGreen() * 0.59
+ c1.getBlue() * .11
+ .5);
Color newGrey = new Color(grey, grey, grey);
image.setRGB(x, y, newGrey.getRGB());
}
}
}
Note that this code is horribly slow. A much faster option is to extract all the pixels from the BufferedImage into an int[], operate on that, and then set it back into the image. This uses the other versions of the setRGB()/getRGB() methods that you'll find in the javadoc.
How do I create an in-memory fully transparent SWT image and draw a black line on it with antialias enabled?
I expect the result to include only black color and alpha values ranging from 0 to 255 due to antialias...
I googled and tried everything that I could... is this possible at all?
This is how I did and it works:
Image src = new Image(null, 16, 16);
ImageData imageData = src.getImageData();
imageData.transparentPixel = imageData.getPixel(0, 0);
src.dispose();
Image icon = new Image(null, imageData);
//draw on the icon with gc
I was able to make this work, although it feels a bit hacky:
Display display = Display.getDefault();
int width = 10;
int height = 10;
Image canvas = new Image(display, width, height);
GC gc = new GC(canvas);
gc.setAntialias(SWT.ON);
// This sets the alpha on the entire canvas to transparent
gc.setAlpha(0);
gc.fillRectangle(0, 0, width, height);
// Reset our alpha and draw a line
gc.setAlpha(255);
gc.setForeground(display.getSystemColor(SWT.COLOR_BLACK));
gc.drawLine(0, 0, width, height);
// We're done with the GC, so dispose of it
gc.dispose();
ImageData canvasData = canvas.getImageData();
canvasData.alphaData = new byte[width * height];
// This is the hacky bit that is making assumptions about
// the underlying ImageData. In my case it is 32 bit data
// so every 4th byte in the data array is the alpha for that
// pixel...
for (int idx = 0; idx < (width * height); idx++) {
int coord = (idx * 4) + 3;
canvasData.alphaData[idx] = canvasData.data[coord];
}
// Now that we've set the alphaData, we can create our
// final image
Image finalImage = new Image(canvasData);
// And get rid of the canvas
canvas.dispose();
After this, finalImage can be drawn into a GC with drawImage and the transparent parts will be respected.
I made it by allocating an ImageData, making it transparent then creating the Image from the data :
static Image createTransparentImage(Display display, int width, int height) {
// allocate an image data
ImageData imData = new ImageData(width, height, 24, new PaletteData(0xff0000,0x00ff00, 0x0000ff));
imData.setAlpha(0, 0, 0); // just to force alpha array allocation with the right size
Arrays.fill(imData.alphaData, (byte) 0); // set whole image as transparent
// Initialize image from transparent image data
return new Image(display, imData);
}
To scale with transparency, I've found that I have to manually set the alpha byte array as shown below. So the alpha ends up with nearest-neighbor anti aliasing.
public static Image scaleImage(Device device, Image orig, int scaledWidth, int scaledHeight) {
Rectangle origBounds = orig.getBounds();
if (origBounds.width == scaledWidth && origBounds.height == scaledHeight) {
return orig;
}
ImageData origData = orig.getImageData();
ImageData imData = new ImageData(scaledWidth, scaledHeight, origData.depth, origData.palette);
if (origData.alphaData != null) {
imData.alphaData = new byte[imData.width * imData.height];
for (int row = 0; row < imData.height; row++) {
for (int col = 0; col < imData.width; col++) {
int origRow = row * origData.height / imData.height;
int origCol = col * origData.width / imData.width;
byte origAlpha = origData.alphaData[origRow * origData.width + origCol];
imData.alphaData[row * imData.width + col] = origAlpha;
}
}
}
final Image scaled = new Image(device, imData);
GC gc = new GC(scaled);
gc.setAntialias(SWT.ON);
gc.setInterpolation(SWT.HIGH);
gc.setBackground(device.getSystemColor(SWT.COLOR_WHITE));
gc.fillRectangle(0, 0, scaledWidth, scaledHeight);
gc.drawImage(orig, 0, 0, origBounds.width, origBounds.height, 0, 0, scaledWidth, scaledHeight);
gc.dispose();
return scaled;
}
A very similar question that has been answered: How to make a color transparent in a BufferedImage and save as PNG
Unfortunately I couldn't formulate an answer for myself out of that source.
Q: I draw a BufferedImage to my Canvas and would simply like to create a method that turns every pixel with the a certain color (in this case: [214, 127, 255] / 0xD67FFF) into a transparent one. The BufferedImage is of type ARGB.
I do not want to save the BufferedImage as a file, simply display it on my canvas.
Thanks in advance.
Iterate over all the pixels and perform the check and make transparent.
for (int y = 0; y < image.getHeight(); ++y) {
for (int x = 0; x < image.getWidth(); ++x) {
int argb = image.getRGB(x, y);
if ((argb & 0x00FFFFFF) == 0x00D67FFF)
{
image.setRGB(x, y, 0);
}
}
}
Make sure the BufferedImage uses an alpha channel, otherwise it will become black.
Note that this will affect your original image.
Edit: Note that I changed the check. Therefor it wouldn't have worked because of I assume your pixels were solid (alpha = 255).
(0xFFD67FFF & 0x00FFFFFF) will result in 0x00D67FFF
And, (0x00D67FFF == 0x00D67FFF)
For a complete solution, like loading, processing and writing, you can use this code:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class TransparentConverter {
private static final Color backColor = Color.GREEN;
private static final int THRESHOLD = 70;
private static final int TRANSPARENT = 0; // 0x00000000;
static File base = new File("C:\\images");
static File base2 = new File("C:\\images2");
public static void main(String[] args) throws IOException {
System.out.println("TransparentConverter.main()");
for (File file : base.listFiles()) {
System.out.println(file);
BufferedImage initImage = ImageIO.read(file);
int width = initImage.getWidth(null),
height = initImage.getHeight(null);
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
g.drawImage(initImage, 0, 0, null);
//System.out.println("before: " + image.getRGB(0, 0));
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
int pixel = image.getRGB(x, y);
Color color = new Color(pixel);
int dr = Math.abs(color.getRed() - backColor.getRed()),
dg = Math.abs(color.getGreen() - backColor.getGreen()),
db = Math.abs(color.getBlue() - backColor.getBlue());
if (dr < THRESHOLD && dg < THRESHOLD && db < THRESHOLD) {
image.setRGB(x, y, TRANSPARENT);
}
}
}
//System.out.println(" after: " + image.getRGB(0, 0));
file = new File(base2, file.getName());
//System.out.println(" " + file);
ImageIO.write(image, "png", file);
}
}
}