Sign Ripple transaction locally using ripple-lib-java

Posted on by yohanes.gultom@gmail.com

Since rippled 1.1.0 disables public signing by default, we either need to host our own API server or sign Ripple transaction locally. Fortunately, ripple-lib-java gives clue on how to do this in one of its example. Long story short, we can use this simple method to do the signing: import java.math.BigDecimal; import com.ripple.core.types.known.tx.txns.Payment; import com.ripple.core.types.known.tx.signed.SignedTransaction;… Read More

Existing PHP catches and bugs

Posted on by yohanes.gultom@gmail.com

I will keep updating this post as part of note whenever I find another catch and bug in PHP. I hope it can help beginner PHP developers (like me) out there to escape hours of confusion and stress .. ? PUT multipart/data bug As explained by this open bug (since 2011), when you submit a multipart/data… Read More

SIFT/SURF BoW for big number of clusters

Posted on by yohanes.gultom@gmail.com

If you spend some time browsing, there are some examples already available for Python SIFT/SURF bag of words (BoW) classifier in the internet. They use clustering (usually K-Means) to build dictionary of visual vocabularies (usually with sklearn or cv2 clustering library) of SIFT/SURF features. However, most of the sample codes that I found can’t properly… Read More

Simple music fingerprinting using Chromaprint in Python

Posted on by yohanes.gultom@gmail.com

Have you ever heard or even use service like Shazam? Cool, right? No, we are not going to make something as magical as it ? But using chromaprint we can create audio fingerprint so that we can do music search by using a music sample. Before we can use chromaprint python library, pyacoustid, we need to install chromaprint… Read More