FingerprintTemplate creation throws ImageDecoder not found error

[Vijay Kanta]

I am trying to save list of candidates to memory in an arraylist. These candidates are coming from a server web api call and the fingerprints were saved in LARGEBLOB in sql. The response from server is in bytes. I use following code to parse and create a template

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byte[] fingerprint = data.getJSONObject("fingerprint").getString("data").getBytes(); // buffer image

try {
    FingerprintTemplate template = new FingerprintTemplate(
        new FingerprintImage()
                .dpi(500)
                .decode(fingerprint)
    );
} catch...

I don’t know whether that’s the right way to get bytes. The response comes like this.

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"fingerprint":{"type":"Buffer","data":[137,80,78,71,13,10,26,10...

The error I get while trying to create fingerprinttemplate from first code

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Fingerprint couldn't be saved: Unsupported image format [ImageIO = 'java.lang.UnsupportedOperationException: Image decoder is not available.', Sanselan = 'java.lang.UnsupportedOperationException: Image decoder is not available.', WSQ = 'java.lang.IllegalArgumentException: This is not a WSQ image.', Android = 'java.lang.IllegalArgumentException: Unsupported image format.'].

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[Robert Važan]

This is not a SourceAFIS problem. Check your JSON parser documentation.

[Vijay Kanta]

Yes, you’re right, I had to Base64 encode the complete byte stream coming from web server before throwing into the fingerprint template.

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JSONArray fingerprintArray = data.getJSONObject("fingerprint").getJSONArray("data"); // buffer image
byte[] fingerprintBytes = new byte[fingerprintArray.length()];
for(int j=0; j<fingerprintArray.length(); j++) {
    fingerprintBytes[j] = (byte) (((int) fingerprintArray.get(j)) & 0xFF);
}

Base64.encodeToString(fingerprintBytes, Base64.DEFAULT);

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