Picrocess - A Go Image Processing Library

Overview

Picrocess is a Go package designed for handling and manipulating images in various formats, including PNG, JPEG, and GIF. It supports a variety of operations such as resizing, cropping, overlaying, and rendering text on images. Additionally, it offers functionality for creating and manipulating GIFs and generating QR codes.

Features

• Image Manipulation: Resize, crop, and overlay images.
• Text Rendering: Add custom text to images with configurable font size and color.
• QR Code Generations: Create customizable QR codes with configurable size and colors.
• Image Formats: Support for PNG, JPEG, and GIF encoding and decoding.
• GIF Creation: Generate GIFs with multiple frames and adjustable delays.
• Font Handling: Load and use TrueType fonts for text rendering.

Installation

To install Picrocess, use the following Go command:

go get github.com/fluffy-melli/picrocess

Example Usage

Below is a simple example that demonstrates how to use Picrocess to load an image, overlay text, and save it as a PNG:

package main

import (
	"fmt"
	"log"

	"github.com/fluffy-melli/picrocess"
)

func main() {
	// Define the content for the QR code (URL in this case)
	content := "https://www.example.com"
	
	// Generate the QR code with the specified content, size, and colors
	qrCode, err := picrocess.NewQRCode(picrocess.NewRGBA(255, 255, 255), picrocess.NewRGBA(0, 0, 0), 256, content)
	if err != nil {
		log.Fatal(err) // Handle error if QR code generation fails
	}

	// Load the specified font for text rendering
	font, err := picrocess.LoadFont("/path/to/font.ttf")
	if err != nil {
		log.Fatal(err) // Handle error if font loading fails
	}

	// Calculate the width of the text "Scan me!" at font size 24
	ow, _ := font.TextSize(24, "Scan me!")

	// Add the text "Scan me!" to the center of the QR code
	err = qrCode.Text(font, picrocess.NewRGBA(255, 0, 0), picrocess.NewOffset((256-ow)/2, 0), 24, "Scan me!")
	if err != nil {
		log.Fatal(err) // Handle error if adding text fails
	}

	// Save the modified QR code image with the text as a PNG file
	err = qrCode.SaveAsPNG("qrcode_output.png")
	if err != nil {
		log.Fatal(err) // Handle error if saving the PNG file fails
	}

	// Print a success message
	fmt.Println("QR code saved as qrcode_output.png")
}

Types

RGBA

The RGBA type represents a color with Red, Green, Blue, and Alpha (transparency) channels.

Constructor

func NewRGBA(r, g, b uint8, a ...uint8) *RGBA

Methods

• Brightness() int: Brightness calculates the perceived brightness of the color.

Rect

The Rect type represents a rectangle with top-left and bottom-right coordinates.

Constructor

func NewRect(w1, h1, w2, h2 uint) *Rect

Offset

The Offset type represents an offset for positioning elements.

Constructor

func NewOffset(w, h uint) *Offset

Font

The Font type represents a TrueType font used for rendering text.

Constructor

func LoadFont(filename string) (*Font, error)

Image

The Image type represents an image with width, height, and a pixel map.

Constructor

func NewImage(w, h uint, color *RGBA) *Image

Methods

• At(x, y uint) *RGBA: Get the color of a pixel at (x, y).
• Set(x, y uint, c *RGBA): Set the color of a pixel at (x, y).
• Overlay(i2 *Image, o *Offset): Overlay another image on top of the current image.
• Resize(w, h uint): Resize the image to the given width and height.
• Crop(r *Rect) *Image: Crop the image to a rectangle.
• Rotate90(): Rotates each pixel by 90 degrees
• RotateMinus90(): Rotates each pixel by -90 degrees
• FlipHorizontal(): Flips the image horizontally (left to right).
• FlipVertical(): Flips the image vertically (top to bottom).
• Round(px uint): Apply rounded corners to the image with a specified radius in pixels.
• Text(font *Font, c *RGBA, o *Offset, size float64, text string): Render text on the image.
• Line(r Rect, c RGBA, thickness float64): Draw a line on the image with the specified thickness.
• Ascii(w, h uint) string: ASCII character based on its brightness level.
• Render() *image.RGBA: Render the image as an image.RGBA type.
• ToPNGByte() ([]byte, error): Convert the image to a PNG byte slice.
• ToJPGByte(quality int) ([]byte, error): Convert the image to a JPG byte slice.
• SaveAsPNG(filename string) error: Save the image as a PNG file.
• SaveAsJPG(filename string, quality int) error: Save the image as a JPG file.

GIF

The GIF type represents an animated GIF with multiple frames and delays.

Constructor

func NewGIF() *GIF

Methods

• Append(image *Image, delay int): Append a frame to the GIF with a specified delay.
• ToGIFByte() ([]byte, error): Convert the GIF to a byte slice.
• SaveAsGIF(filename string) error: Save the GIF as a file.

QRCode

The QRCode type represents a QR code image.

func NewQRCode(content string, size int, fgColor RGBA, bgColor RGBA) (*Image, error)

Supported Formats

• PNG: Using png.Encode and png.Decode for encoding and decoding.
• JPEG: Using jpeg.Encode and jpeg.Decode for encoding and decoding.
• GIF: Using gif.EncodeAll and gif.DecodeAll for encoding and decoding.

Notes

• The library requires the golang.org/x/image/webp package for WebP support.
• The github.com/golang/freetype package is used for rendering text with TrueType fonts.

License

This library is open source and available under the MIT License.