pngtotxt

Console program to convert a PNG image (e.g. a QR-Code) to text using block graphic symbols.

The primary goal to develop this program has been to support Aqbanking console tools like aqhbci-tool4 and aqbanking-cli in displaying QR-Code-based photoTANs without the need of invoking a graphical UI.

Table of Contents

• Overview
• Dependencies
• Invocation/running
• Internationalization
• Building & Installing
• Supported Platforms
• Getting the Source via Git

Overview

pngtotxt is a tiny tool to convert a PNG image to text-based block graphic.

Home Page: https://github.com/pkzw/pngtotxt

Dependencies

pngtotxt depends on

• libiconv (see https://www.gnu.org/software/libiconv/) and
• libpng (see http://www.libpng.org/pub/png/libpng.html).

Running

The following example will convert a QR-Code in file qrcode.png to a text file qrcode.txt:

$ pngtotxt qrcode.png > qrcode.txt

Performing a SEPA bank transfer with aqbanking-cli displaying photoTAN as console output:

$ aqbanking-cli --opticaltan=pngtotxt sepatransfer --iban=...

See program help for more information:

$ pngtotxt --help
Usage: pngtotxt [OPTIONS] [CTY] IFN
This program converts a PNG image to text using block graphic symbols.

Options:
  -a, --append      Append text to output file
  -h, --help        Display detailed help information
  -o, --output=OFN  Output file name (default is standard output)
  -v, --version     Display version information

CTY is the content-type of the input file (Default is 'image/png').
IFN is the name of the input file (required). Use '-' or 'stdin' to read from standard input.
OFN is the name of the output file.

Internationalization

The program is not yet internationalized and thus available in English language only.

Building & Installing

pngtotxt uses CMake to handle the build process.

The follwing example shows how to build the program on a Debian-based system:

# Install prerequisites
sudo apt update
sudo apt install build-essential cmake git libpng-dev
# Clone project from GitHub
mkdir -p ~/git
cd ~/git
git clone https://github.com/pkzw/pngtotxt
# Configure build
mkdir -p ~/build/pngtotxt
cd ~/build/pngtotxt
cmake ~/git/pngtotxt
# Build project
make
# Install
sudo make install

For building on Windows platform see README.W32.md

Supported Platforms

pngtotxt has been tested to work with the following operating systems:

• GNU/Linux -- x86
• Windows -- x86

pngtotxt can probably be made to work on any platform for which the dependencies can be fulfilled and a C compiler is available, given sufficient expertise and effort.

Getting Source with Git

You can browse the code at https://github.com/pkzw/pngtotxt. Clone URIs are on that page, or if you have a Github account you can fork it there.

Thank you.