Reading Image Files

Java 2D
#1

I’m doing generic research on reading images in Java.

My interests are the usual: minimizing memory allocation and minimizing loading time.

For example:
Earlier this week I dusted off the JPEG file format (technically the EXIF file format specs) and learned how to extract the thumbnails out of JPEGs. So now our users can browse folders of their megapixel images in peace and efficiency. (Are there packages out there that help in extracting thumbnails: this saves a lot of hard work in some cases.)

And earlier today I wrote a replacement to the MediaTracker class (at least as far as my needs are concerned):

I haven’t dived much into the use of the ImageIO class. Can anyone comment on whether they’ve had more success with ImageIO than generic Toolkit.createImage() calls?

Also sometime in coming months we’re going to look at tiling images at work. (For an application that is supposed to be able to open megapixel images and edit them.) Does anyone have any thoughts/references on that? I saw a Java app handle tiled images beautifully once at some sort of Apple workshop; but the developers were tight-lipped about how they did it. (Might be JNI for all I know?) I know in theory the Java image framework supports tiles, and databuffers support different banks, but I think by default only 1 tile and 1 bank are used (?).

I realize this is a very vague thread; I’m just asking for seasoned advice (or suggestions for articles, books, etc.) on the subject. And hopefully if I can be of use to someone reading this thread I’ll chime in too. :slight_smile:

#2

ImageIO allows you to work with tiled images, and the performance
had improved in recent releases (recent 5.0 updates and 6.0
especially).

Also, for large images you might want to take a look at
Java Advanced Imaging library - see here: https://jai.dev.java.net/ .
They also have optimized ImageIO plugins.

Dmitri

#3

I took the easy way out for this. I just had the game load up a series of images from disk based on a naming scheme and put them in the object and then cached them in memory. For example: big_tank_#, it’d loop until it didn’t find anyone more pictures with the next #. I’m going to write an algorithm that handles the amount and replacement for the cached images so they do not take too much memory.