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Resize Blob image before saving to Play Framework

I am developing a webpage using Java and Play Framework 1.2.4.

I have a simple file input form that allows the user to upload an image file. Sometimes the image is too big and it takes a long time to display the image, so I need to resize the image. How can I do this with the game?

I know the function Images.resize (from, to, w, h), I tried to use it, but it doesn't work as I expected, here is my code:

public static void uploadPicture(long product_id, Blob data) throws FileNotFoundException {
   String type = data.type();
   File f = data.getFile();
   Images.resize(f, f, 500, -1);
   data.set(new FileInputStream(f), type);

   Product product = Product.findById(product_id);
   product.photo = data;
   product.save();
}
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3 answers


Perhaps you need to define a different destination file instead of overwriting the original file:



File f = data.getFile();
File newFile = new File("Foo.jpg"); // create random unique filename here
Images.resize(f, newFile, 500, -1);
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Images modified by the Java standard libraries are of poor quality. I would use ImageMagic with Java libraries like im4java . ImageMagic must be installed on the server.

So, for example, resizing an image to a thumb with a white background might look like this:

private static void toThumb(File original) {
        // create command
        ConvertCmd cmd = new ConvertCmd();

        // create the operation, add images and operators/options
        IMOperation op = new IMOperation();
        op.addImage(original.getPath());
        op.thumbnail(THUMB_WIDTH, THUMB_WIDTH);
        op.unsharp(0.1);
        op.gravity("center");
        op.background("white");
        op.extent(THUMB_WIDTH, THUMB_WIDTH);
        op.addImage(original.getPath());

        try {
            // execute the operation
            cmd.run(op);
        } catch (IOException ex) {
            Logger.error("ImageMagic - IOException %s", ex);
        } catch (InterruptedException ex) {
            Logger.error("ImageMagic - InterruptedException %s", ex);
        } catch (IM4JavaException ex) {
            Logger.error("ImageMagic - IM4JavaException %s", ex);
        }

    }


Add im4java to your dependencies:

require:
    - play ]1.2,)
    - repositories.thirdparty -> im4java 1.1.0

repositories:

    - im4java:
        type:       http
        artifact:   http://maven.cedarsoft.com/content/repositories/thirdparty/[module]/[module]/[revision]/[module]-[revision].[ext]
        contains:
            - repositories.thirdparty -> *
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You can use http://imagemagick.org along with http://im4java.sourceforge.net/ to convert images . Use something like this, but with your custom parameters:

createThumb(from, to, "-thumbnail", "60x60", "-quality", "100", "-format", "jpg"); 
private void createThumb(File from, File to, String... args) throws ImageConvertException {
            ConvertCmd cmd = new ConvertCmd();
            IMOperation op = new IMOperation();
            op.addImage(from.getAbsolutePath());
            op.addRawArgs(args);
            op.addImage(to.getAbsolutePath());
            try {
                cmd.run(op);
            } catch (Exception e) {
                throw new ImageConvertException(e);
            }
}
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