hi... only because an image is saved in 300dpi doesn't make it automatically hi-res. DPI is a virtual measure and only useful for print purposes. even the 72dpi used for "screen resolution images" is misleading since display resolutions these days have somewhat come along since that term has been coined. for example my screen res on laptop is 128dpi, while  the same number of pixels on my iMac are only 99dpi... Code:

println(dist(0,0,1680,1050)/15.4); // 128.64
println(dist(0,0,1680,1050)/20); // 99.05 

so what constitutes high resolution for bitmaps is purely down to the number of pixels used for an image. simply increase the size of your sketch or use the new built in PDF export feature or one of the other vector format export libraries for infinite resolution.

hth!

Hey tintin,

no worries - am not sure what you mean with "but I only can save it in an java format" - you can use the saveFrame() to export an image as TIFF or TGA...

the 2 lines of code were purely to demonstrate how I arrived at the DPI settings for my 2 displays (both at 1680x1050).

println(dist(0,0,1680,1050)/15.4) taken apart means:

* calculate the diagonal number of pixels of the display (dist() is the same as pythagoras)

* then we divide the result by the physical size of the display (in inches) to get the resolution in dots-per-inch...

* println() prints out the final result in the console

If you put the following code into Processing and run it, then click on the applet and press a key - an image will be saved in that sketch's folder.
Code:

//testing how to save an image
int wide = 100;
int high = 100;
void setup(){
  size(wide, high);
}
void draw(){
  rect(10,10,20,20);
}
void keyPressed(){
  saveFrame();
}
 

Now if you want 300 dots per inch, that's like 300 pixels per inch. So you need to do some simple multiplication. There are 2.54cm to the inch by the way. So for the width of the image the formula would be:

(width_in_centimeters / 2.54) * 300

As a hint, Photoshop will use 49.8 megabytes making an A3 image at 300 dpi