Adding multiple images to one canvas in Python - python

I want to load a number of images from harddrive and place them on a larger white background. And I want to do it in Python. I am wondering what is the best way of doing that. I am using a windows machine and I can use any library I want. Any pointer to a webpage or a sample code that can point me to a good direction would be appreciated.
Something like this:

A very popular image processing library for Python is PIL. The official PIL tutorial might be useful, especially the section about "Cutting, Pasting and Merging Images".

PIL isn't enough. Try also with PIL the aggdraw library.
But aggdraw also isn't enough. It works poorly with transparency. I mean 0.5-1 gray pixel around opaque object over the transpparent area.

Related

How can i transform Image1 to Image2 using matplotlib.pyplot or another library in python

How can i transform Image1 to Image2 using matplotlib.pyplot or another library in Python?
Image 1:
Image 2:
(This image turned out to be confidential,i removed it because i can't delete the post. Sorry for the inconvenience)
Any help is appreciated.
Have a look at the Python Imageing Library (which also has python bindings, by the way), especially the ImageFilter module.
But tools like ImageMagick or one of the built-in filters in Gimp might be more suitable for experimenting.
Is it the experimental data and already filtered from image 1 to image 2 by someone else? I wonder whether you have the point spread function along with the raw image 1?

Moving crops within the same image

Tried looking in the PIL module but couldn't find this covered.
I have an image, and I need to take a cropped piece of the image and move it to a different area within the same image. Simple enough, but I will need to do this for thousands of images, so I will do batch image processing.
PIL seems too basic for this, any other libraries?
Actually, PIL looks like it can do it very well, if you want to copy and paste rectangular areas.
Check the documentation on the crop and paste methods on image, on the documentation here:
http://effbot.org/imagingbook/image.htm
If you need non-rectangular areas, though, you will have to resort to more sophisticated handling, but that does not preclude you from doing it with PIL.
Yes, check OpenCV.
How to crop images with opencv in python
The Python wrapper for the GD library should do what you need:
copyTo(image[, (dx,dy)[, (sx,sy)[, (w,h)]]])
copy from (sx,sy), width sw and height sh to destination image (dx,dy)

Python: Manipulating a 16-bit .tiff image in PIL &/or pygame: convert to 8-bit somehow?

Hello all,
I am working on a program which determines the average colony size of yeast from a photograph, and it is working fine with the .bmp images I tested it on. The program uses pygame, and might use PIL later.
However, the camera/software combo we use in my lab will only save 16-bit grayscale tiff's, and pygame does not seem to be able to recognize 16-bit tiff's, only 8-bit. I have been reading up for the last few hours on easy ways around this, but even the Python Imaging Library does not seem to be able to work with 16-bit .tiff's, I've tried and I get "IOError: cannot identify image file".
import Image
img = Image.open("01 WT mm.tif")
My ultimate goal is to have this program be user-friendly and easy to install, so I'm trying to avoid adding additional modules or requiring people to install ImageMagick or something.
Does anyone know a simple workaround to this problem using freeware or pure python? I don't know too much about images: bit-depth manipulation is out of my scope. But I am fairly sure that I don't need all 16 bits, and that probably only around 8 actually have real data anyway. In fact, I once used ImageMagick to try to convert them, and this resulted in an all-white image: I've since read that I should use the command "-auto-levels" because the data does not actually encompass the 16-bit range.
I greatly appreciate your help, and apologize for my lack of knowledge.
P.S.: Does anyone have any tips on how to make my Python program easy for non-programmers to install? Is there a way, for example, to somehow bundle it with Python and pygame so it's only one install? Can this be done for both Windows and Mac? Thank you.
EDIT: I tried to open it in GIMP, and got 3 errors:
1) Incorrect count for field "DateTime" (27, expecting 20); tag trimmed
2) Sorry, can not handle images with 12-bit samples
3) Unsupported layout, no RGBA loader
What does this mean and how do I fit it?
py2exe is the way to go for packaging up your application if you are on a windows system.
Regarding the 16bit tiff issue:
This example http://ubuntuforums.org/showthread.php?t=1483265 shows how to convert for display using PIL.
Now for the unasked portion question: When doing image analysis, you want to maintain the highest dynamic range possible for as long as possible in your image manipulations - you lose less information that way. As you may or may not be aware, PIL provides you with many filters/transforms that would allow you enhance the contrast of an image, even out light levels, or perform edge detection. A future direction you might want to consider is displaying the original image (scaled to 8 bit of course) along side a scaled image that has been processed for edge detection.
Check out http://code.google.com/p/pyimp/wiki/screenshots for some more examples and sample code.
I would look at pylibtiff, which has a pure python tiff reader.
For bundling, your best bet is probably py2exe and py2app.
This is actually a 2 part question:
1) 16 bit image data mangling for Python - I usually use GDAL + Numpy. This might be a bit too much for your requirements, you can use PIL + Numpy instead.
2) Release engineering Python apps can get messy. Depending on how complex your app is you can get away with py2deb, py2app and py2exe. Learning distutils will help too.

Histogram Equalization

I am a beginner in Python. I want to make a small project on histogram equalisation. Basically I want to include changing contrast, color and crop option etc in my project. I am blank right now. Please suggest something. I am very keen to make this project but how to start?
Python's PIL module has methods for controlling contrast, color, and cropping.
You can use PythonMagick. It suports histogram equalization:
import PythonMagick
img = PythonMagick.Image("original.png")
img.equalize()
img.write("equalized.png")
PythonMagick is not very well documented itself, but its API directly corresponds to Magick++ API. Use Magick++ documentation for reference.
If PIL is enough for you, stick with PIL, it is better supported. I installed PythonMagick from the Ubuntu package, the project page does not open for me.

PIL vs RMagick/ruby-gd

For my next project I plan to create images with text and graphics. I'm comfortable with ruby, but interested in learning python. I figured this may be a good time because PIL looks like a great library to use. However, I don't know how it compares to what ruby has to offer (e.g. RMagick and ruby-gd). From what I can gather PIL had better documentation (does ruby-gd even have a homepage?) and more features. Just wanted to hear a few opinions to help me decide.
Thanks.
Vince
PIL is a good library, use it. ImageMagic (what RMagick wraps) is a very heavy library that should be avoided if possible. Its good for doing local processing of images, say, a batch photo editor, but way too processor inefficient for common image manipulation tasks for web.
EDIT: In response to the question, PIL supports drawing vector shapes. It can draw polygons, curves, lines, fills and text. I've used it in a project to produce rounded alpha corners to PNG images on the fly over the web. It essentially has most of the drawing features of GDI+ (in Windows) or GTK (in Gnome on Linux).
PIL has been around for a long time and is very stable, so it's probably a good candidate for your first Python project. The PIL documentation includes a helpful tutorial, which should get you up to speed quickly.
ImageMagic is a huge library and will do everything under the sun, but many report memory issues with the RMagick variant and I have personally found it to be an overkill for my needs.
As you say ruby-gd is a little thin on the ground when it comes to English documentation.... but GD is a doddle to install on post platforms and there is a little wrapper with some helpful examples called gruby thats worth a look. (If you're after alpha transparency make sure you install the latest GD lib)
For overall community blogy help, PIL's the way.

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