Learn how to build an image type converter with just a few simple lines of Python code. Whether it’s a single image file or all files in a directory, you can easily convert between different formats.
Installing Required Libraries
You need to install the Pillow Python library to build an image-type converter in Python. This library advances the image-processing capabilities of your Python interpreter. You can create a general image processing tool using several modules of this library. Some of the most useful are the Image, ImageFile, ImageFilter, and ImageStat modules.
Run the following command in the terminal to install the Pillow Python library:
Once you have Pillow installed on your system, you are ready to work with images.
Loading and Displaying Properties of an Image
First you need to import the Image module from the PIL library to set up the code. Next, you need to use the Image.open() method to load the image and assign it to a variable. Once you have loaded the image, you can display it using the show() method.
The image that you passed as a parameter to the open() method will open up after you execute the code. This is a good first step, as a sanity check, to ensure you have successfully installed the library on your system.
The Image module provides several other properties that you can use to get more information about the image.
You should see some meaningful data with no errors:
How to Convert Image Format Using Python
You can simply convert the file format of an image using the save() method. You just need to pass the new filename and extension as a parameter to the save() method. The save() method will automatically identify the extension that you passed and then save the image in the identified format. But before using the save() method, you may need to specify the mode of the image (RGB, RGBA, CMYK, HSV, etc.).
How to Convert an Image From PNG to JPG and JPG to PNG
You need to pass the string filename.jpg as a parameter to the save() method to convert image files in any format (PNG, GIF, BMP, TIFF, etc.) to JPG format. Also, you need to provide the mode of the image. The following code converts an image from PNG format to JPG format:
RGB (3x8-bit pixels, true color)
RGBA (4x8-bit pixels, true color with transparency mask)
CMYK (4x8-bit pixels, color separation)
HSV (3x8-bit pixels, Hue, Saturation, Value color space)
You can convert an image in any format to PNG format using the save() method. You just need to pass the PNG image as a parameter to the save() method. The following code converts an image from JPG format to PNG format:
How to Convert an Image to Any Other Format Using Python
Similar to the steps above, you can convert an image in any format to any other format using the save() method. You just need to provide the correct image extension (.webp, .png, .bmp, etc.) to the save() method. For example, the following code converts an image from PNG to WebP format:
Error Handling for Missing Image Files
In case the code is not able to find the input image, it will throw an error. You can handle this using the FileNotFoundError Python exception.
Converting All the Images in a Directory to a Different Format
If there are several image files in a directory, that you want to convert to a different format, you can easily do so with just a few lines of code in Python. You need to import the glob library to iterate through the files in the current directory or inside a given folder. The following code converts all the JPG images in the current directory to PNG format:
If you want to convert a different set of files, change the string parameter you pass to the glob() method.
Build a GUI Using Python
Python libraries like Pillow make it easy to develop tools to deal with images in Python. You can perform tasks quickly with a command line interface but a GUI is essential to create a user-friendly experience. You can create more specialized GUI applications using Python frameworks like Tkinter and wxPython.
