Why isn't my BufferedImage being converted to a LWJGL Image properly? - java

so I'm trying to add TrueTypeFonts to my game. And basically, I've got it to read a TrueTypeFont from a file, and it correctly reads it to a BufferedImage. But when I pass the BufferedImage to my Sprite constructor (for loading images to be used with OpenGL), it completely breaks it. Have a look at the following images:
So here's the constructor for my Sprite utility class, which will take the BufferedImage and convert it to a ByteBuffer and bind it to an ID.
public Sprite(BufferedImage img) {
// this will show the BufferedIamge in a modal dialog, see Fig. 2
JOptionPane.showMessageDialog(null, null, "Another", JOptionPane.YES_NO_OPTION, new ImageIcon(img.getScaledInstance(img.getWidth() * 4, img.getHeight() * 4, Image.SCALE_REPLICATE)));
int[] pixels = new int[img.getWidth() * img.getHeight()];
img.getRGB(0, 0, img.getWidth(), img.getHeight(), pixels, 0, img.getWidth());
this.width = img.getWidth();
this.height = img.getHeight();
ByteBuffer buff = BufferUtils.createByteBuffer(img.getWidth() * img.getHeight() * 4);
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
int pixel = pixels[y * img.getWidth() + x];
buff.put((byte) ((pixel >> 16) & 0xFF));
buff.put((byte) ((pixel >> 8) & 0xFF));
buff.put((byte) (pixel & 0xFF));
buff.put((byte) ((pixel >> 24) & 0xFF));
}
}
buff.flip();
id = GL.glGenTextures();
GL.glEnable(GL_TEXTURE_2D);
GL.glBindTexture(GL_TEXTURE_2D, id);
GL.glPixelStorei(GL.GL_UNPACK_ALIGNMENT, 1);
GL.glPixelStorei(GL.GL_PACK_ALIGNMENT, 1);
GL.glTexImage2D(GL_TEXTURE_2D, 0, GL.GL_RGBA, width, height, 0, GL_RGBA, GL.GL_UNSIGNED_BYTE, buff);
}
Fig. 2 - The Image that we pass through, looks good!
Fig. 3 - When I render the image, note I can render any other image and it turns out ok. Even transparent ones, too.
Ignore the blob at the bottom, that's me trying to render a string of text!
Any help greatly appreciated, I've spent a while trying to suss out how to implement fonts.

Without actually running a test project, I would suspect that the reason that it looks like this is that the following code:
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
causes the pixels to be added by scanning down first and not across. To go across, flip the for loops:
for (int y = 0; y < img.getHeight(); y++) {
for (int x = 0; x < img.getWidth(); x++) {

Related

Fast way to convert BufferedImage to byte array, and add alpha

I'm using the following to add overlay to a video; but it doesn't perform well because it requires to process every pixels (which is A LOT of work if you have full-HD at 50 frames/sec!)
private static byte[] convert(BufferedImage image, int opacity)
{
int imgWidth = image.getWidth();
int imgHeight = image.getHeight();
byte[] buffer = new byte[imgWidth * imgHeight * 4]
int imgLoc = 0;
for(int y=0; y < imgHeight; y++)
{
for(int x=0; x < imgWidth; x++)
{
int argb = image.getRGB(x, y);
imgBuffer[(imgLoc*4)+0] = (byte)((argb>>0)&0x0FF);
imgBuffer[(imgLoc*4)+1] = (byte)((argb>>8)&0x0FF);
imgBuffer[(imgLoc*4)+2] = (byte)((argb>>16)&0x0FF);
int alpha = ((argb>>24)&0x0FF);
if (opacity < 100)
alpha = (alpha*opacity)/100;
imgBuffer[(imgLoc*4)+3] = (byte)alpha;
imgLoc++;
}
}
How can I re-write this code to perform better? I've tried many different things, e.g.:
image.getRGB(0, 0, image.getWidth(), image.getHeight(), null, 0, image.getWidth());
((DataBufferByte) image.getData().getDataBuffer()).getData()
But none of these seem to work; the overlay doesn't show up, while the slower method at least shows the overlay.
PS: I know the ARGB is converted to ABGR in the function above; I'll fix that later. The overlay should still show, albeit in different colors

glReadPixels returns more data than expected

I want to save a video of what I am showing with openGL using JOGL. To do this, I am writing my frames to pictures as follows and then, once I have saved all frames I'll use ffmpeg. I know that this is not the best approach but I still don't have much clear how to accelerate with tex2dimage and PBOs. Any help in that direction would be very useful.
Anyway, my problem is that if I run the opengl class it works but, if I call this class from another class, then I see that the glReadPixels is trhowing me an error. It always returns more data to buffer than memory has been allocated to my buffer "pixelsRGB". Does anyone know why?
As an example: width = 1042; height=998. Allocated=3.119.748 glPixels returned=3.121.742
public void display(GLAutoDrawable drawable) {
//Draw things.....
//bla bla bla
t++; //This is a time variable for the animation (it says to me the frame).
//Save frame
int width = drawable.getSurfaceWidth();
int height = drawable.getSurfaceHeight();
ByteBuffer pixelsRGB = Buffers.newDirectByteBuffer(width * height * 3);
gl.glReadPixels(0, 0, width,height, gl.GL_RGB, gl.GL_UNSIGNED_BYTE, pixelsRGB);
BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
int[] pixels = new int[width * height];
int firstByte = width * height * 3;
int sourceIndex;
int targetIndex = 0;
int rowBytesNumber = width * 3;
for (int row = 0; row < height; row++) {
firstByte -= rowBytesNumber;
sourceIndex = firstByte;
for (int col = 0; col < width; col++) {
int iR = pixelsRGB.get(sourceIndex++);
int iG = pixelsRGB.get(sourceIndex++);
int iB = pixelsRGB.get(sourceIndex++);
pixels[targetIndex++] = 0xFF000000
| ((iR & 0x000000FF) << 16)
| ((iG & 0x000000FF) << 8)
| (iB & 0x000000FF);
}
}
bufferedImage.setRGB(0, 0, width, height, pixels, 0, width);
File a = new File(t+".png");
ImageIO.write(bufferedImage, "PNG", a);
}
NOTE: With pleluron's answer now it works. The good code is:
public void display(GLAutoDrawable drawable) {
//Draw things.....
//bla bla bla
t++; //This is a time variable for the animation (it says to me the frame).
//Save frame
int width = drawable.getSurfaceWidth();
int height = drawable.getSurfaceHeight();
ByteBuffer pixelsRGB = Buffers.newDirectByteBuffer(width * height * 4);
gl.glReadPixels(0, 0, width,height, gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, pixelsRGB);
BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
int[] pixels = new int[width * height];
int firstByte = width * height * 4;
int sourceIndex;
int targetIndex = 0;
int rowBytesNumber = width * 4;
for (int row = 0; row < height; row++) {
firstByte -= rowBytesNumber;
sourceIndex = firstByte;
for (int col = 0; col < width; col++) {
int iR = pixelsRGB.get(sourceIndex++);
int iG = pixelsRGB.get(sourceIndex++);
int iB = pixelsRGB.get(sourceIndex++);
sourceIndex++;
pixels[targetIndex++] = 0xFF000000
| ((iR & 0x000000FF) << 16)
| ((iG & 0x000000FF) << 8)
| (iB & 0x000000FF);
}
}
bufferedImage.setRGB(0, 0, width, height, pixels, 0, width);
File a = new File(t+".png");
ImageIO.write(bufferedImage, "PNG", a);
}
The default value of GL_PACK_ALIGNMENT set with glPixelStore is 4. It means that each row of pixelsRGB should start at an address that is a multiple of 4, and the width of your buffer (1042) times the number of bytes in a pixel (3) isn't a multiple of 4. Adding a little padding so the next row starts at a multiple of 4 will make the total byte size of your buffer larger than what you expected.
To fix it, set GL_PACK_ALIGNMENT to 1. You could also read the pixels with GL_RGBA and use a larger buffer, since the data is most likely to be stored that way both on the GPU and in BufferedImage.
Edit: BufferedImage doesn't have a convenient 'setRGBA', too bad.

Detect & remove a range of colors from Java BufferedImage

I'm building an application that uses OCR to read text from an image (using Tess4J for Google's Tesseract), but I want to ignore the tan-colored text and only read the grey.
In the image below, for instance, I only want to read "Ricki" and ignore "AOA".
http://i.imgur.com/daCuTbB.png
To accomplish this, I figured removing the tan color from the image before performing OCR was my best option.
/* Remove RGB Value for Group Tag */
int width = image.getWidth();
int height = image.getHeight();
int[] pixels = new int[width * height];
image.getRGB(0, 0, width, height, pixels, 0, width);
for (int i = 0; i < pixels.length; i++) {
//If pixel is between dark-tan value and light-tan value
if (pixels[i] > 0xFF57513b && pixels[i] < 0xFF6b6145) {
// Set pixel to black
System.out.println("pixel found");
pixels[i] = 0xFF000000;
}
}
image.setRGB(0, 0, width, height, pixels, 0, width);
But this code removes almost all of the grey text as well. You aren't able to simply compare hex color values for a range of values the way I have. Is there another way to approach detecting a range of colors? Or a better different approach to this problem?
haraldK pointed me in the right direction by mentioning converting RGB. Bit shifting to get individual r, g, and b int values from the hex value allowed me to compare the color within a range and black out a range of colors from the image.
int baser = 108; //base red
int baseg = 96; //base green
int baseb = 68; //base blue
int range = 10; //threshold + and - from base values
/* Set all pixels within +- range of base RGB to black */
for (int i = 0; i < pixels.length; i++) {
int a = (pixels[i]>>24) &0xFF; //alpha
int r = (pixels[i]>>16) &0xFF; //red
int g = (pixels[i]>>8) &0xFF; //green
int b = (pixels[i]>>0) &0xFF; //blue
if ( (r > baser-range && r < baser+range) &&
(g > baseg-range && g < baseg+range) &&
(b > baseb-range && b < baseb+range) ) {
pixels[i] = 0xFF000000; //Set to black
}
}

Why BufferedImage is not working well?!! Is it because I misused it?

I want to copy a gray image using BufferedImage from getRGB() to int[][] and then to setRGB(). The problem is that the size of image is different from the size of the one that the program outputs it. The original image has file size = 176 KB, whereas the output image has file size = 154 KB. I have to say that when you see the two image, all of the human-being would say it is the same, but in terms of binary bits, there are different in something that I would like to know.
Maybe some of you will say it doesn't matter, as long as image is the same when you look at it. In fact, during the processing of some noise project, this is a huge problem, and I suspect that this is the reason why I have the problem.
I just want to know if there are other method than BufferedImage to produce int[][] and then to create the output?
This is the code that I'm using:
public int[][] Read_Image(BufferedImage image)
{
width = image.getWidth();
height = image.getHeight();
int[][] result = new int[height][width];
for (int row = 0; row < height; row++)
for (int col = 0; col < width; col++)
result[row][col] = image.getRGB(row, col);
return result;
}
public BufferedImage Create_Gray_Image(int [][] pixels)
{
BufferedImage Ima = new BufferedImage(512,512, BufferedImage.TYPE_BYTE_GRAY);
for (int x = 0; x < 512; x++)
{
for (int y = 0; y < 512; y++)
{
int rgb = pixels[x][y];
int r = (rgb >> 16) & 0xFF;
int g = (rgb >> 8) & 0xFF;
int b = (rgb & 0xFF);
int grayLevel = (r + g + b) / 3;
int gray = (grayLevel << 16) + (grayLevel << 8) + grayLevel;
Ima.setRGB(x, y, pixels[x][y]);
}
}
return Ima;
}
public void Write_Image(int [][] pixels) throws IOException
{
File outputfile;
outputfile = new File("Y0111.png");
BufferedImage BI = this.Create_Gray_Image(pixels);
ImageIO.write(BI, "png", outputfile);
System.out.println("We finished writing the file");
}
See the figure, you see file size = 176 KB (this is the original image) and file size = 154 KB (this is the output image).
The difference of size is not a problem. It's certainly because of different compression/encoding.
A BufferedImage is in fact a 1D array of size width * height * channel. getRGB is not the easiest/fastest way to manipulate a BufferedImage. You can use the Raster (faster than getRGB, not the fastest, but it takes care of the encoding for you). For a gray level image:
int[][] my array = new int[myimage.getHeight()][myimage.getWidth()] ;
for (int y=0 ; y < myimage.getHeight() ; y++)
for (int x=0 ; x < myimage.getWidth() ; x++)
myarray[y][x] = myimage.getRaster().getSample(x, y, 0) ;
The opposite way:
for (int y=0 ; y < myimage.getHeight() ; y++)
for (int x=0 ; x < myimage.getWidth() ; x++)
myimage.getRaster().setSample(x, y, 0, myarray[y][x]) ;
The fastest way to do it is to use the DataBuffer, but then you have to handle the image encoding.

Converting grayscale image pixels to defined scale

I'm looking to use a very crude heightmap I've created in Photoshop to define a tiled isometric grid for me:
Map:
http://i.imgur.com/jKM7AgI.png
I'm aiming to loop through every pixel in the image and convert the colour of that pixel to a scale of my choosing, for example 0-100.
At the moment I'm using the following code:
try
{
final File file = new File("D:\\clouds.png");
final BufferedImage image = ImageIO.read(file);
for (int x = 0; x < image.getWidth(); x++)
{
for (int y = 0; y < image.getHeight(); y++)
{
int clr = image.getRGB(x, y) / 99999;
if (clr <= 0)
clr = -clr;
System.out.println(clr);
}
}
}
catch (IOException ex)
{
// Deal with exception
}
This works to an extent; the black pixel at position 0 is 167 and the white pixel at position 999 is 0. However when I insert certain pixels into the image I get slightly odd results, for example a gray pixel that's very close to white returns over 100 when I would expect it to be in single digits.
Is there an alternate solution I could use that would yield more reliable results?
Many thanks.
Since it's a grayscale map, the RGB parts will all be the same value (with range 0 - 255), so just take one out of the packed integer and find out what percent of 255 it is:
int clr = (int) ((image.getRGB(x, y) & 0xFF) / 255.0 * 100);
System.out.println(clr);
getRGB returns all channels packed into one int so you shouldn't do arithmetic with it. Maybe use the norm of the RGB-vector instead?
for (int x = 0; x < image.getWidth(); ++x) {
for (int y = 0; y < image.getHeight(); ++y) {
final int rgb = image.getRGB(x, y);
final int red = ((rgb & 0xFF0000) >> 16);
final int green = ((rgb & 0x00FF00) >> 8);
final int blue = ((rgb & 0x0000FF) >> 0);
// Norm of RGB vector mapped to the unit interval.
final double intensity =
Math.sqrt(red * red + green * green + blue * blue)
/ Math.sqrt(3 * 255 * 255);
}
}
Note that there is also the java.awt.Color class that can be instantiated with the int returned by getRGB and provides getRed, getGreen and getBlue methods if you don't want to do the bit manipulations yourself.

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