Processing 1.0 - Processing Discourse - Loading images in draw?

holva

Loading images in draw?
May 5^th, 2009, 12:24pm

I'm working on a project right now where I scrape images from google in Max/MSP/Jitter and then load them into a sketch in processing. What I am doing is downloading the images to a folder and then sending the file name to processing over a UDP port to processing to load the image while the sketch is running. I figure that this would require loading images in draw? My main problem is that I can't figure out how to load images into processing while a sketch is running. Considering the files are downloaded in realtime I can't specify the file names before loading the sketch. In addition, I am planning on there to be eventually be hundreds of images, so saving each file as a different name (ex. google1, google2, google3,) and loading them into an array doesnt seem to be quite feasible either. <-- EDIT this doesnt even need to be addressed at this point... if I can get one image loaded into processing while the sketch is running I'm sure I could figure it all out from there.

sorry if I'm not incredibly clear.

« Last Edit: May 5^th, 2009, 2:06pm by holva »

naus3a

Re: Loading images in draw?
Reply #1 - May 5^th, 2009, 12:47pm

Quote:

I am planning on there to be eventually be hundreds of images, so it seems that saving each file as a different name (ex. google1, google2, google3,) so loading them into an array isnt in that way doesnt seem to be quite feasible either.

why not? you could name them inserting in their name an incremental number. if you don't like the idea you could make image array or arraylist; in this case you could simply call each image just with an index.

also, depending on the logic of you program, you could also think to just "forget" old images and concentrate just on the newest one:
Code:

imagename = getImageName(); // the function youre using to get the image name
image(imagename, x, y);

this way you each draw cycle puts a new image at x,y.

PhiLho

Re: Loading images in draw?
Reply #2 - May 5^th, 2009, 2:00pm

You probably cannot load all the images before starting draw(), both for time spent and for memory constraints.
As naus3a said, you can load images on demand, freeing memory if you no longer need them.
I usually advice against loading images in draw(), because it is slow and the way people do it, they would load an image 60 times per second!
But of course you can make that loading conditional, on a given time frame, etc.
The problem is that loadImage() will indeed stop the drawing until the image is loaded. Fortunately, Processing authors thought of that, and made requestImage(), allowing asynchronous loading.

holva

Re: Loading images in draw?
Reply #3 - May 5^th, 2009, 2:03pm

Sorry, I just re-read my post and saw how sloppy and poorly-worded it was.

My main problem is that I won't have the images downloaded before the sketch runs. What I'm looking for is a way to load the images into processing while the sketch is running. I can't load the images into the sketch before running it because they haven't been downloaded yet.

a = loadImage(message); //message = name of the file scraped from google, sent over the UDP from Max

Is that more clear? Thanks so much for your help! I'm completely new to p5.

holva

Re: Loading images in draw?
Reply #4 - May 5^th, 2009, 2:09pm

PhiLho wrote on May 5^th, 2009, 2:00pm:

You probably cannot load all the images before starting draw(), both for time spent and for memory constraints.
As naus3a said, you can load images on demand, freeing memory if you no longer need them.
I usually advice against loading images in draw(), because it is slow and the way people do it, they would load an image 60 times per second!
But of course you can make that loading conditional, on a given time frame, etc.
The problem is that loadImage() will indeed stop the drawing until the image is loaded. Fortunately, Processing authors thought of that, and made , allowing asynchronous loading.

Aha! It looks like this may be what I need. Thank you, I'm looking into it now.