Can I access ImageMagick API with Python?
I would recommend using Wand (explanations follows).
I was looking for proper binding to ImageMagick library, that would:
- work error/problem free
- be regularly maintained and up to date
- allow nice objective Python
But indeed python API (binding) has too many different (mostly discontinued) versions. After reading a nice historical overview by Benjamin Schweizer it has all become clear (also see his github wiki):
- GraphicsMagick
- PythonMagick - first implementation
- PythonMagickWand/Achim Domma - first Wand - a CDLL implementation
- PythonMagickWand/Ian Stevens
- MagickFoo - included in python-magickwand
- Wand/Hong Minhee - the latest project
Now Wand is just a (reduced) C API to the ImageMagick ".. API is the recommended interface between the C programming language and the ImageMagick image processing libraries. Unlike the MagickCore C API, MagickWand uses only a few opaque types. Accessors are available to set or get important wand properties." (See project homepage)
So it is already a simplified interface that is easer to maintain.
This has worked for me for the following command to create an image from text for the letter "P":
import subprocesscmd = '/usr/local/bin/convert -size 30x40 xc:white -fill white -fill black -font Arial -pointsize 40 -gravity South -draw "text 0,0 \'P\'" /Users/fred/desktop/draw_text2.gif'subprocess.call(cmd, shell=True)
I found no good Python binding for ImageMagick, so in order to use ImageMagick in Python program I had to use subprocess
module to redirect input/output.
For example, let's assume we need to convert PDF file into TIF:
path = "/path/to/some.pdf"cmd = ["convert", "-monochrome", "-compress", "lzw", path, "tif:-"]fconvert = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)stdout, stderr = fconvert.communicate()assert fconvert.returncode == 0, stderr# now stdout is TIF image. let's load it with OpenCVfilebytes = numpy.asarray(bytearray(stdout), dtype=numpy.uint8)image = cv2.imdecode(filebytes, cv2.IMREAD_GRAYSCALE)
Here I used tif:-
to tell ImageMagick's command-line utility that I want to get TIF image as stdout stream. In the similar way you may tell it to use stdin stream as input by specifying -
as input filename.