loadimage, big images and memory...

General Discussion Other

jooora

loadimage, big images and memory...

in General Discussion • Other • 1 year ago

Hi!

I have to show a picture of 8624 x 12545px.

My program can display it with a few memory by storing it to disk with a sort of "quad tree" structure (a lot of smaller images).

My problem comes the first time I load the big image:

To store it as a bunch of small files, I have to load it at least once, without displaying it. (only cut & save).

But this operation "PImage img = loadImage(theBigPic.png)" uses too much memory.

So that I get the exception "java.lang.OutOfMemoryError: Java heap space".

I upped the JVM max memory space to 1500Mo (can't put more, or the jvm cannot be instancied).

So I'd like to find a way to load the image using less memory space. (I don't need to keep transparency, and I don't need to display it). Any Idea?

Replies(15)

calsign

Re: loadimage, big images and memory...

1 year ago

Can you split the file into different pieces (from your system's file manager)?

You could also try increasing the JVM heap size from the File > Preferences dialogue.

quarks

Re: loadimage, big images and memory...

1 year ago

By my calculations the image will require approximately 433Mb of RAM (minimum) and you will need space for the smaller images to be saved (actually create one small image copy part of the big image save it and then reuse it for the next small image.On my system I can increase available RAM to 2048Mb so try calsign's second option.

If that doesn't work then use a graphics package (e.g. GIMP or Paint.NET) to make the smaller files

jooora

Re: loadimage, big images and memory...

1 year ago

Hi,

I don't want to split the file by an other way: my program should do it itself.

I can not increase the JVM heap size more. Anyway I think that 1.5Go is even too much for a simple program. It's not very clean to tell your customer "you can not run the program if you don't have 1.5 Go RAM free"...

" the image will require approximately 433Mb of RAM"

=> That's why I'm sure there is a way to load it without the need of 2Go of ram. But with processing loadimage, it requires more than 1Go of RAM, which is not good at all... :s

edit:

I looked at this:

Program not running: 1.44G RAM used in my system (I have 3G)

Program running before loading image: 1.77G (+330 M)

"loadImage()" => crash at 2.28G (+840M)

Why does the program crash (heap space) at only 840M, with a JVM configured at 1500M ?

I find it out!

The crash is here:

PImage.java:285

/**
* Construct a new PImage from a java.awt.Image. This constructor assumes
* that you've done the work of making sure a MediaTracker has been used
* to fully download the data and that the img is valid.
*
* @param img assumes a MediaTracker has been used to fully download
* the data and the img is valid
*/
public PImage(java.awt.Image img) {
format = RGB;
if (img instanceof BufferedImage) {
BufferedImage bi = (BufferedImage) img;
width = bi.getWidth();
height = bi.getHeight();
pixels = new int[width * height];
WritableRaster raster = bi.getRaster();
raster.getDataElements(0, 0, width, height, pixels);
if (bi.getType() == BufferedImage.TYPE_INT_ARGB) {
format = ARGB;
}
} else { // go the old school java 1.0 route
width = img.getWidth(null);
height = img.getHeight(null);
pixels = new int[width * height]; //<===== CRASH HERE
PixelGrabber pg =
new PixelGrabber(img, 0, 0, width, height, pixels, 0, width);
try {
pg.grabPixels();
} catch (InterruptedException e) { }
}
}

So, I'll try to do my class extending PImage to be able to load an image using less memory,

and with the possibility to load only a part of the image.

Before I start, any suggestion?

quarks

Re: loadimage, big images and memory...

1 year ago

I have done some experiments. The following program created an image of 8268x12545 pixels and when ran used an additional 440Mb of RAM which is roughly what is expected.

void setup(){
PGraphics pg = createGraphics(8624, 12545,JAVA2D);
}

I then create an image file of the same size using Paint.NET and used this program to load it. This required an additional 950Mb of memory, over twice as much as expected. I don't know what the extra RAM is used for or whether thiis a Processing thing or a Java thing.

void setup(){
PImage img = loadImage("huge.jpg");
}

Perhaps someone else knows more.

quarks

Re: loadimage, big images and memory...

1 year ago

Just noticed the code in your latest post.

The PImage constructor you are using assumes that you already have a java.awt.Image loaded into RAM which is then to be converted into a PIMage. So thats at least 440Mb for the Image and presumeably 950Mb for the PImage.

jooora

Re: loadimage, big images and memory...

1 year ago

PImage uses this constructor when you do loadImage("huge.jpg");

So it explains the heavy space.

I just wonder how to bypass the 440M extra space...

aureliokrg

Re: Re: loadimage, big images and memory...

6 months ago

Hi joora,

did you go through this issue? I have to load a huge amont of 1280x720 png images (like approx 500) during runtime of my sketch and I would be interested to know how you managed the load your big image...

thks!

jooora

Re: loadimage, big images and memory...

6 months ago

Hi,

Yes I found an issue for my problem,

I load the big images without processing functions, but with awt.

It fix my loading problem:

Here is the class:

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class MyImage {
/**
* Charge une image via une méthode awt : gain de mémoire.
* Retourne null en cas d'échec
* @param String filemane le chemin du fichier image
* @return BufferedImage
*/
public static BufferedImage loadImage(String filemane) {
return loadImage(new File(filemane));
}
/**
* Charge une image via une méthode awt : gain de mémoire.
* Retourne null en cas d'échec
* @param file le fichier image
* @return BufferedImage
*/
public static BufferedImage loadImage(File file) {
/** @link http://www.coderanch.com/t/344416/GUI/java/do-you-crop-image-Java **/
try {
return ImageIO.read(file);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* Retourne une partie de l'image donnée, à partir de coordonnées en pourcent (0 à 100)
* @param image
* @param px origine x en pourcent (0-100)
* @param py origine y en pourcent (0-100)
* @param pw largeur en pourcent (0-100)
* @param ph hauteur en pourcent (0-100)
* @return BufferedImage
*/
public static BufferedImage cropImagePercent(BufferedImage image, float px, float py, float pw, float ph) {
int x = (int) (image.getWidth() *px/100f);
int y = (int) (image.getHeight()*py/100f);
int w = (int) (image.getWidth() *pw/100f);
int h = (int) (image.getHeight()*ph/100f);
return image.getSubimage(x, y, w, h);
}
/**
* Retourne une image redimentionnée de img
* @param img
* @param newW : nouvelle largeur en px
* @param newH : nouvelle hauteur en px
* @return
*/
public static BufferedImage resize(BufferedImage img, int newW, int newH) {
// return Thumbnails.of(img).size(newW, newH).asBufferedImage(); //http://code.google.com/p/thumbnailator/
BufferedImage resized = new BufferedImage(newW, newH, BufferedImage.TYPE_INT_RGB);
Graphics2D g = resized.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, newW, newH);
g.drawImage(img.getScaledInstance(newW, newH, Image.SCALE_SMOOTH), 0, 0, newW, newH, null);
g.dispose();
return resized;
}
/**
* Sauvegarde l'image sur le disque
* @param image Image à sauvegarder
* @param filePath Chemin où sauvegarder l'image
* @return true ou false si exception lors de l'enregistrement
*/
public static boolean save(BufferedImage image, String filePath) {
try {
ImageIO.write(image, "png", new File(filePath));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
return true;
}
}

Call :

BufferedImage image = MyImage.loadImage("image.png");

or, if you need the path :

File file = new File("image.png");
String path = file.getAbsolutePath();
BufferedImage image = MyImage.loadImage(file);

Then, I resize my image in diffrent sizes (actually, I do better than that), and I save them into files and free its memory.

When I need to display one, I reload from a file with the good size and display it.

If you want to use 500 images, you'll not be able to load all at once.

so it depends of your need of these images,

you may want to resize them one by one and only keep in memory the thumbnail,

or you can load the images you need form files each time that you need them...

What is your use of the 500 images?

aureliokrg

Re: loadimage, big images and memory...

6 months ago

Hi,

first of all, thanks for your response.

My aim is to draw each of my 500 images depending of messages sent by a thread (the messages are MIDI messages sent by themidibus library). Each time that a specific message is listened, I want to display a specific image. So I need to store the images, update my list of images which have to be displayed every time that a MIDI messaged is received and be able to retrieve these images to display it in the draw() method.

You are right, I won't be able to load all of the 500 images at once, so I am thinking of two way of proceeding for the image loading:

- to load the images by groups through a GUI (after the setup())

- to load all of the images at once, but in separated threads that will load groups (during the setup()). This can be more efficient in terms of CPU usage

Your use of bufferedImages is really interested, and could fit to my needs. I was already thinking about using multithreading and bufferedImages as shown here. But in this example the bufferedImages are converted to PImages and stored this way, so it won't help me to save memory

If I well understand what your are doing, you do not resize a thumbnail when you need to display it, you rather keep them in different sizes and display as there are, exactly like in a quadtree. is it true? If I use thumbnails, I still need to display them at the same size : 1280*720. How do you display your images, do you convert it in PImages during runtime?

So I wonder, if I use the thumbnails or if I rather store the images outside of the sketch,

will I be able to resize and display them when needed, without lose of time or quality of the image ?

jooora

Re: loadimage, big images and memory...

6 months ago

Yes, I made a quadtree system.

Because I had very huge images (12000*8000px), I had to store them into the hard disk, in thousand of smaller files.

At runtime, I load from harddisk (into PImage) the pieces of images I need to display. The other images are not stored in the memory. This causes a very small lag when I load a lot of images at once from harddisk, because of the low HDD speed to access data.

Your case is different :

You don't need to load the images at setup.

You just need to display some images in a 1280*720 window.

So, why not try this:

Use 2 buffers (PGraphics) as 2 layers: the first one is the background (BG). You never clean it!

The second one is where you draw your images moving, it's your foreground (FG). You always redraw it.

You always do this: BG.draw(); FG.draw();

1) Setup: You load the list of your images paths, but not the image objects.

2) At runtime, when you need to display an image, you load it from hard disk, and redraw it on your buffer FG as long as the image needs to move.

3) When you no longer need to animate your image, draw it on BG (over the previous images) and destroy the loaded image: because you don't clean BG, it will always be visible.

4) Repeat 2) & 3) for new images when you need to display them.

Total memory space: size of BG (1280*720*ARGB) + FG (1280*720*ARGB) + the current loaded image(s) being animated on FG.

If needed, use more layers!

But you'll never display 50 visible images of 1280*720 in one screen, so it could be easy to find a way to remove all non-visible images from memory.

aureliokrg

Re: loadimage, big images and memory...

6 months ago

Your proposition is really clever, in case I need some images to be always drawn... Nevertheless I should explain you more precisely what I want to do with the images:

Considering the MIDI message, I'm using 3 parameters: the MIDI channel, the pitch (which note is played) and the velocity (how loud the note is played). Depending on the channel and pitch, I pick a specific image to display. Depending on the velocity I either display the image at some opacity or not display it at all. So the images don't move, but they all are likely to be displayed and then to disappear. All displayed images are blended together in the ADD mode, they all fit in the same window of 1280*720 pixels.

I think your are right and I should only keep in memory the images I need to display, but I don't think the BG idea will do the job.

For instance, if 20 notes are played at once and keep being played, I could draw it in the BG. then, if only 1 of these 20 notes stop being played at some point, I couldn't retrieve it and make it disappear if I don´t keep in memory all the instances of PImage drawn during runtime... That what you said, I need to keep in memory the current loaded images being animated, but as all images can appear or disappear at any time, the BG doesn't appear useful for my problem. Or maybe I didn't get you well.

Also, I am afraid that loading the PImages in runtime when needed will lead to latency (even if I do it in separated threads, if 20 notes or more are played at once and the 20+ images have to be loaded, it can last few seconds and so my system won't be real time-reactive).

So maybe I could do something between keeping all the PImages in memory, which is awful, and loading specific PImages when needed, which I think can lead to latency when there are a lot... Maybe I could keep BufferedImages in memory and load it as PImages when needed? Or do you have any other thought ?

Thank for your help!

jooora

Re: loadimage, big images and memory...

6 months ago

Ok, let's try your idea, or increase your computer memory ^^

Then see if it's ok or not.

In my opinion, half definition images (640*380) with zoom x2 + smooth would be enough, and would allow you to preload the 500 images using less than 1Go of memory.

aureliokrg

Re: loadimage, big images and memory...

6 months ago

What you advice me is something like this :

- load my 1280*720 images as bufferedImages

- resize it with something like your resize(BufferedImage img, int newW, int newH) fonction

- create PImages of 640*380 from the resized bufferedImages

- while drawing it, use scale()

Am I right ?

jooora

Re: loadimage, big images and memory...

6 months ago

Yes, let's try this and see if it's correct for your use?

aureliokrg

Re: loadimage, big images and memory...

6 months ago

okay, I'll let you know. tks!

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