Read Modifiers in Wand Python

Read modifier refers to immediately modify input image or file format after reading or to make the image perfect to manipulate just after reading the image. This can be done by using the filename parameter of Image() function.

For instance, let us say we want to read an image of (100 x 100) dimensions/aspect ratio but the original image is of (200 X 200) dimensions/aspect ratio. So we can use Read modifier in order to convert image to (100 X 100) dimensions/aspect ratio just after reading it.

We can use read modifiers to display specific frames from the .gif file. Also to select specific pages from pdf files

Types of Read Modifiers:

1. Read frames/pages
2. Read Resize
3. Read Crop

Syntax: with Image(filename=’filename.format[read_modifier]’) as modified_Read:

Example 1: Let us say we need to read only the first page from pdf and convert it in .png format.

# Import Image from wand.image module
from wand.image import Image

    # Read first page of pdf using Image() function
    with Image(filename ='document.pdf[0]') as first_page:

        # convert pdf page to image file
        first_page.convert("png")

        # save final image
        first_page.save(filename = "first_page_image.png")

Output:

Example 2:

Input:

# Import Image from wand.image module
from wand.image import Image

# Read first six frames of gif using Image() function
with Image(filename='sample.gif[0-5]') as f:
    #save final image
    f.save(filename = "final.gif")

Output:

Example 3: In this we will perform Read Resize.

Input:

# Import Image from wand.image module
from wand.image import Image

# Read first six frames of gif using Image() function
with Image(filename ='initial.jpg[400x300]') as resized_image:
    # convert  jpg image file to png image file
    resized_image.convert("png")
    # save final image
    resized_image.save(filename = 'final.png')

Output :

Example 4: In this we will perform Read Crop and then save it in another format.

# Import Image from wand.image module
from wand.image import Image

# Read first six frames of gif using Image() function
with Image(filename ='sample.gif[100x100 + 50 + 75]') as cropped_image:
    # convert gif file to png file
    cropped_image.convert("png")
    # save final image
    cropped_image.save(filename = 'final.png')

Input:

Output: