Scale an image which is stored as a byte[] in Java
- by Sergio del Amo
I upload a file with a struts form. I have the image as a byte[] and I would like to scale it.
FormFile file = (FormFile) dynaform.get("file");
byte[] fileData = file.getFileData();
fileData = scale(fileData,200,200);
public byte[] scale(byte[] fileData, int width, int height) {
// TODO
}
Anyone knows an easy function to do this?
public byte[] scale(byte[] fileData, int width, int height) {
ByteArrayInputStream in = new ByteArrayInputStream(fileData);
try {
BufferedImage img = ImageIO.read(in);
if(height == 0) {
height = (width * img.getHeight())/ img.getWidth();
}
if(width == 0) {
width = (height * img.getWidth())/ img.getHeight();
}
Image scaledImage = img.getScaledInstance(width, height, Image.SCALE_SMOOTH);
BufferedImage imageBuff = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
imageBuff.getGraphics().drawImage(scaledImage, 0, 0, new Color(0,0,0), null);
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
ImageIO.write(imageBuff, "jpg", buffer);
return buffer.toByteArray();
} catch (IOException e) {
throw new ApplicationException("IOException in scale");
}
}
If you run out of Java Heap Space in tomcat as I did, increase the heap space which is used by tomcat. In case you use the tomcat plugin for Eclipse, next should apply:
In Eclipse, choose Window
Preferences Tomcat JVM Settings
Add the following to the JVM
Parameters section
-Xms256m -Xmx512m
