non destructive resize of larger image

jeffmarc

I used resize to scale a 1000x1000 image to 500x500 But then the original 1000x1000 image is gone. I have to reload it each time, do my thresholding and then scale it down for display each time.

Is there a way to keep the original image after thresholding each time and display the scaled version without having to reload the original each time?

A non destructive resizing to a new smaller image without using brute force loops to create the new scaled image with a new name? if i do a img.resize the original img is gone.

koogs

Copy the original image into a tmp image. Resize the tmp image.

jeffmarc

ok tryed that

PImage tmpimg
PImage img

tmpimg=loadImage(image.png)
img=tmpimg

(at this point both height and width =1000) tmpimg.resize(100,100)

I printed height and width of both at this point and img is now 100x100 as well!

I didn't resize img

tmpimg.resize changed both?????

jeffmarc

     PImage tmpimg;
     PImage img;

     tmpimg=loadImage("test.png");
     print("tmpimg width="+tmpimg.width+" height="+tmpimg.height+"\n");
     img=tmpimg;
     print("img width="+img.width+" height="+img.height+"\n");
     tmpimg.resize(480,480);
     print("tmpimg width="+tmpimg.width+" height="+tmpimg.height+"\n");
     print("img width="+img.width+" height="+img.height+"\n");

what gets printed

   tmpimg width=1000 height=1000
   img width=1000 height=1000
   tmpimg width=480 height=480
   img width=480 height=480

GoToLoop

https://forum.Processing.org/two/discussion/18109/how-can-i-clone-an-image-object

https://forum.Processing.org/two/discussions/tagged?Tag=get()

jeffmarc

So tmpimg and img are not totally different mem space variables trying to understand how processing works compared to C if i create 2 image variable type PImage are they llike pointers in C? They just point to a space? So is there a syntax for taking a whole image and duplicating it in another space and setting a pointer to point to it?

GoToLoop

... if I create 2 image variable type PImage are they like pointers in C?

Pointers, references, memory addresses mean the same thing! (:|
Just use PImage's get() method in order to get a clone of it: *-:)
https://Processing.org/reference/PImage_get_.html

koogs

There's a copy () method on the pimage class.

Untested but i'd've thought this would work

tmpImg = img.copy();

quark

Yes copy() will work

PImage src = loadImage("blah blah blah.png");
PImage dest = src.copy();
dest.resize(500,500);
dest.save("smaller blah blah blah.png");

jeffmarc

I get error : The method copy(int,int,int,int,int,int,int,int) is the type PImage is not applicable for the arguments() So do i need to provide values for copy or is copy() acceptable in another version? Using 2.2.1

quark

copy() has NO arguments it makes a full copy of the image which you can resize leaving the original unaffected.