How to convert text to image and how does ttf font works


Here is how do we convert text to image using python:

Python code to convert text to image

from PIL import Image, ImageDraw, ImageFont

def text_to_png(text, font_path, font_size):
# Load the font
font = ImageFont.truetype(font_path, font_size)

# Create image with transparent background
image_size = (500, 500) # You might want to dynamically set this based on text dimensions
image = Image.new("RGBA", image_size, (255, 255, 255, 255))

# Initialize drawing context
draw = ImageDraw.Draw(image)

# Get text size
text_size = draw.textsize(text, font=font)

# Calculate position
text_x = (image_size[0] - text_size[0]) / 2
text_y = (image_size[1] - text_size[1]) / 2

# Apply text to image
draw.text((text_x, text_y), text, font=font, fill="black")

# Save image
image.save("word.png")

text_to_png("hello", "ARIAL.TTF", 50)


Where we can see, one key is to use the right ttf font.

A TrueType Font (TTF) file is a font file format that was developed by Apple and Microsoft in the late 1980s as a competitor to Adobe’s Type 1 fonts used in PostScript. It has become a widely adopted standard for font display.

How TrueType Fonts Work:

TrueType fonts contain both the screen and printer font data in a single component, making the font scalable to any size. Here’s a bit about how they work:

Outline Descriptions: TrueType fonts are made up of outlines for each character (glyph), defined by quadratic Bézier curves. These outlines are scalable to any size, which means that they can be resized without losing quality.

Hinting: To ensure that these outlines look good when displayed at small sizes on low-resolution screens, TrueType fonts include “hints”. These are instructions that adjust the display of the glyph to make it more readable at various sizes and resolutions.

Glyph Mapping: TrueType fonts include a ‘cmap’ table that maps character codes to the corresponding glyph. This table is used to select the correct glyph when a character is displayed.

Embedding Rights: The font files can contain data that specify embedding rights, determining if and how the font can be embedded in a document or used on a webpage.

Rendering: When a character is to be displayed, the font engine reads the outline from the TTF file, applies hinting instructions for the current resolution, and then rasterizes the outline into pixels on the screen or into dots for a printer.

Including Fonts for Different Languages:

To include fonts that support different languages, the font must have the necessary glyphs and character mappings for the characters used in those languages. Here’s how you can include such fonts:

Unicode Support: Ensure that the TrueType font supports Unicode, which provides a unique number for every character, no matter the platform, program, or language. Unicode fonts can support many different languages and scripts.

Font Selection: Choose a font that includes the range of Unicode characters needed for the languages you wish to support. For instance, if you need to support both Latin and Cyrillic scripts, the font must have the corresponding glyphs for both scripts.

OS and Application Support: The operating system and the application you are using must support the language and script you intend to display. They must be able to handle input methods for different languages and correctly apply the language-specific rules of shaping and layout.


Author: robot learner
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