CODEWITHSUNDEEP
javaimagegoogle-app-engineimage-processing
quarks
quarks

Reputation: 35316

Image conversion with GAE Image API

I'm trying to understand how to deal with GAE Image api, to automatically convert between image format to JPEG.

Here is my code:

byte[] oldImageData = model.getImage();
Image oldImage = ImagesServiceFactory.makeImage(oldImageData);
LOG.info("Image format - " + oldImage.getFormat().toString());
model.setImage(oldImage.getImageData()); // byte array must be JPEG

The oldImageData byte array here can be a byte array of a JPEG or PNG image, or worst case not an image.

Finally, what I need to do is to make sure that oldImageData is a byte array for a JPEG image.

Upvotes: 2

Views: 974

Answers (2)

Peter Knego
Peter Knego

Reputation: 80340

ImagesService imagesService = ImagesServiceFactory.getImagesService();
Image oldImage = ImagesServiceFactory.makeImage(oldImageData);

// this throws an exception if data is not image or unsupported format
// you can wrap this in try..catch and act accordingly 
oldImage.getFormat();

// this is a dummy transform that does nothing
Transform transform = ImagesServiceFactory.makeCrop(0.0, 0.0, 1.0, 1.0);

// setting the output to JPEG
OutputSettings outputSettings = new OutputSettings(ImagesService.OutputEncoding.JPEG);
outputSettings.setQuality(100);

// apply dummy transform and output settings
Image newImage = imagesService.applyTransform(transform, oldImage, outputSettings);

byte[] newImageData = newImage.getImageData();

Upvotes: 6

UVM
UVM

Reputation: 9914

You can check the magic number of any image and based on that you can take action. The following link will give you the list of magic numbers and you can use that in a utilty for future purpose

image magic number

Upvotes: 0

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