ReceiptBudget

Managing expenses made easy

Why Keep a Budget?

So that you know where your money goes

And to help you make financial plans

I came to Cluj in 2011, to college.

The first month, I expected to have a lot of expenses.

By the end of the second month:

Where's all my money?

I had X at the beginning of the month and now I have X - X = 0

I had to do something

An Excel spreadsheet with four columns: when, what, how much and where

Version 1:

Not good Enough

Version 2:

Now including some reports!

Pretty...

... boring

and complicated

Version 3

Meet ReceiptBudget

A web app written in Python

Features

Adding expenses by just taking a photo of the receipt

all the details, none of the work

Much more detailed reports

visualizing expenses on a map
slicing and dicing data based on month, day, shop

And backwards compatible with what I had until now

THE OCR ENGINE

had to be custom built

receipts are space constrained, so the font is usually very squeezed
Tesseract (best free alternative) was hit-and-miss - sometimes it worked, sometimes it didn't

I developed a custom tool just to gather all the data for training

STEPS

the image is preprocessed

straightened
edges removed
binarized

uses Random Forests for character segmentation and a linear SVM for character recognition
accuracy: ~85%

The letter data is then used to determine the content of each line using a naive, rule based system

Biggest bottleneck in the pipeline

if one digit in a date is not recognized correctly

"23/10/13" => "S3/10/13"

if one letter in TOTAL is changed, how to tell it's not an item?

TOTA - brand of professional photography lamps

Built uSING:

All three free, open-source libraries for scientific

computing, machine learning and computer vision

The Dashboard

The goal is to get some insight into spending patterns

If I know when and where I usually spend more money, I can start doing something about it

(at least be more careful when walking past my favorite shop)

THE map

The most expenses were at Kaufland it's to be expected, it's a grocery store

But the second most expensive one is the area around my university

I often go to the nearby store to buy snacks

If I were to buy them somewhere else, I could probably save some money

The charts

Observations

I spend a lot of money on Mondays

very little on Saturdays

There is a peak at the beginning of the month

probably taxes and rent

I spend a lot of money in odd places

the Unknown column, where I didn't write down the place of spending

Built USING

d3.js

dc.js

crossfilter

to do

deep learning for the OCR engine

Google's doing it, so it must be good

use a probabilistic classifier instead of a rule based one for understanding line contents
dashboard should make predictions, not just give reports