Ok...

The read/write-locations had to be exactly the same. It's working now! It is kinda weird though, i wrote to the folder where the sketch is located (which is standard) so i thought no additional path was required and just the filename would suffice but it appeared to need the full path too.

FRid

loadImage() takes the image from the data folder inside the sketch folder. While FileOutputStream is pure Java and has no concept of such folder: you can use FileOutputStream(dataPath("mod.jpg")) to get the same path.

// using the OR operator |, if the bit isn't already on this will turn it on
buffer[whichByte] |= bitMask;

What does this do? Use "whichByte" OR "bitMask" as index for buffer? Then on what is this choice depending on?

No. The | symbol is outside of the brackets, so it applies to buffer at the given index, not to whichByte. And that's not a OR in an English way (one or the other), but a bit or: search (Wikipedia for example) for boolean logic (bit operations).

Hi,

Thanks for helping. I get it now. Interweave/add the b[whichbyte] with the random one to get weird effects.

Two more questions though, is there a command/function/method (forgive me, i'm bad at taxonomy) that you can call which checks where the sketch is exactly located and returns it as a string. Right now i've entered the full path (C:/*/*/*/something.jpg) to read/write but it would be really nice if i could just call "dataPath" for example to get the location of the .pde and append "/data" to it. If not present already in P5 maybe in java?

Second question - The OF-example runs a bit different. First it reads the image into a buffer (ofBufferFromFile), it then rearranges and creates a imagefile from that buffer (ofBufferToFile), displays it and saves it again. Is there an equivalent in P5? Because in OF if you adjust the example-code a bit you can rearrange the bytes every frame and the image never breaks, it'll just keep deterioriating more and more, it's always getting read. In P5 after a few loops it breaks without recovering. I assume "BufferedImage" is the way to go for this?

Anyway thanks for the help,
FRid

1) You have already dataPath() to get the path to the data folder, why get the sketch's path and add /data to it? Processing does that already... But if you need the sketch's path anyway, you can get it with sketchPath(someFileName), or just the sketchPath variable (there is also a dataPath variable).
2) Yes, I always warned against this method of adding noise anywhere in a raw image file, as it actually breaks the compression scheme and can bring chaos in the headers, etc. Some image readers can recover from simple errors, but will end in crashing (having pointers in memory leading to some code!) or worse! After all, that's a way to infect some data files, making common image libraries with security flaw to allow to introduce arbitrary, hidden code in a system...
So, to deteriorate an image, and only this image, load it (with loadImage), use loadPixels, alter the pixels[] array, use updatePixels[] and save the result with saveImage. No loadBytes messing...

1) Thanks, very handy, nice!

2) Yeah ok, you can also do it manually but this gives a totally different aesthetic to it and is much more cumbersome to realize. (or there is some magic-trick i have yet to explore (if so i'd love to hear about it ofcourse :)

FRid

In that case, your method seems OK, but perhaps you need to be more precise in your target, avoiding the headers and only messing with the compressed data. You have to look how it is done in OF.

In OF it's kinda avoided by using

int whichByte = int(random(b.length*0.2, b.length));

b.length multiplied by 0.2 so it avoids the first 10000 bytes (depending ofcourse on filesize) but this also leaves some space at the top untouched so i adjusted it a little. But i think the trick in OF is that because you first load it into a buffer and rearrange it, it is then interpreted as imagedata and then saved so i think the interpretation clears out some misstakes maybe? Although it did break a few times in OF the other day so their method is also not flawless.

Was trying out the BufferedImage-method but unfortunately without results. Can't think of a way to convert BufferedImage to Image (and after that PImage)

File inputFile = new File("1.jpg");
BufferedImage input = ImageIO.read(inputFile);
BufferedImage output = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

Or to convert 2dGraphics into something i can display.

Graphics2D g2d = output.createGraphics();
PGraphics pg = createGraphics(width, height, P2D);
g2d.drawImage(pg.image, 0, 0, width, height, null);

I get the feeling this is all still a bit over my head :(
FRid

" you first load it into a buffer and rearrange it, it is then interpreted as imagedata"
Well, that's exactly what loadImage does already... The pixels[] array is what you call imagedata.
The OF method is empirical and flawed... A better way, but much harder, would be to look at the definition of Jpeg images, to know the size of the header, to skip it accurately. But even then, the header probably declare a size of image, and if you randomize bits in the compressed data, you will end with a different size, which will confuse image readers.

Thanks. Yeah, this does seem like the best way to go indeed.

About the BufferedImage and graphics2d, i've found some posts about this but it doesn't seem to work. Especially the graphics2d it should work if i call "image(g2d,0,0);)" right? Instead it is saying "can not convert graphics2d into Pgraphics2d"

1. import java.awt.image.BufferedImage;
   import java.awt.image.ConvolveOp;
   import java.awt.image.Kernel;
   import java.awt.Graphics2D;
   import java.awt.Graphics;
   import java.io.File;
   import java.io.IOException;
   
   import javax.imageio.ImageIO;
   PImage img;
   
   void setup() {
     size(700,700);
     noLoop();
     println(sketchPath("GlitchBufferedImage.pde"));
    
     try {
       File inputFile = new File("1.jpg");
       BufferedImage input = ImageIO.read(inputFile);
       Graphics2D g2d = input.createGraphics();
       PGraphics pg = createGraphics(width, height, P2D);
       g2d.drawImage(pg.image, 0, 0, width, height, null);
      
       image(g2d,0f,0f);
     } catch(IOException e) {
      
     } 
   }
   
   void draw() {
    
   }
   

You can write:
PImage pi = new PImage(input);
I think.

Unfortunately that didn't work. Nothing shows, no picture and what's even weirder no errors too.

BufferedImage may not be that good of an idea after all. I'll try to find out about the headers.
Thanks for all the help though and have a great new year's eve (dependant on where you are ofcourse, (maybe you allready had it)

FRid