golang picture hide

In modern society, digital technology continues to develop, and the issue of personal information protection in the online world has become increasingly important. In order to protect data privacy, people seek various encryption methods, among which picture hiding technology is a common encryption method. Golang, as an efficient programming language, can also be used to implement image hiding technology.

What is picture hiding?

The so-called picture hiding is to hide another picture or information in one picture, so that external users can only see the external picture and turn a blind eye to the hidden picture or information. This method can protect data privacy well and enhance data security to a certain extent.

Golang’s picture hiding principle

Golang, as an efficient programming language, is not only used for writing website back-end programs. Golang's image processing library "image" provides a wealth of image processing functions, which can perform various processing operations on images, such as image cropping, rotation, scaling, color adjustment, etc.

Picture hiding technology essentially embeds one picture into another picture. The embedding process is divided into two steps: first, convert the image to be hidden into a binary string, and then embed the binary string into the target image. When embedding, we can use the pixel data of the target image as a carrier and store the information to be hidden in certain bits in the pixel data in sequence. This hidden information can be another picture, text, audio, etc. When the recipient obtains the image, he or she can decrypt the information hidden in it.

Implementing picture hiding

We can use the image package provided by Golang to implement picture hiding. The following are the steps to implement:

Step 1: Read the target image

Use the Decode function of Golang's image package to decode the image file into an Image object in the Go language. In this example, we will use this function to read the target image.

func readImage(path string) (image.Image, error) {
    f, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer f.Close()
    
    img, _, err := image.Decode(f)
    if err != nil {
        return nil, err
    }
    
    return img, nil
}

Step 2: Convert the image to be hidden into a binary string

We can use the ReadFile function in Golang's io/ioutil package to read the image to be hidden and convert it to Binary string.

func readData(path string) ([]byte, error) {
    data, err := ioutil.ReadFile(path)
    if err != nil {
        return nil, err
    }
    
    return data, nil
}

Step 3: Hide Data

In order to hide binary data, we need to create a new Image object and modify its pixel data. Since each pixel usually occupies four bytes (32 bits), we can use the last bit of each pixel to store data. For example, if the data to be hidden is 01100101, we can store it in the pixel of the target image. The specific method is to set the last bit of the pixel to 0 or 1 to store the data (because the last bit of a pixel is a bit, So one byte of data in 8 pixels can be stored).

func hideData(img image.Image, data []byte) (image.Image, error) {
    bounds := img.Bounds()
    
    newImg := image.NewRGBA(bounds)
    
    idx := 0    
    var r, g, b, a uint32
    
    for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
        for x := bounds.Min.X; x < bounds.Max.X; x++ {
            r, g, b, a = img.At(x, y).RGBA()
            if idx < len(data)*8 {
                bitIdx := idx % 8
                bits := uint32(data[idx/8])
                mask := uint32(0x00 << bitIdx)
                if bits&(1<<7-bitIdx) > 0 {
                    mask |= uint32(0x01 << bitIdx)
                }
                r = (r & 0xFFFE) | (mask & 0x01)
                g = (g & 0xFFFE) | ((mask >> 1) & 0x01)
                b = (b & 0xFFFE) | ((mask >> 2) & 0x01)
                a = (a & 0xFFFE) | ((mask >> 3) & 0x01)                
            }
            newImg.Set(x, y, color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)})
            idx++
        }
    }
    
    return newImg, nil
}

Step 4: Save the new image with hidden data

To save the new image with hidden data, use the Encode function of Golang's image package.

func saveImage(path string, img image.Image) error {
    f, err := os.Create(path)
    if err != nil {
        return err
    }
    defer f.Close()
    
    err = png.Encode(f, img)
    if err != nil {
        return err
    }
    
    return nil
}

Complete code:

package main

import (
    "fmt"
    "image"
    "image/color"
    "image/png"
    "io/ioutil"
    "os"
)

func main() {
    if len(os.Args) < 2 {
        fmt.Println("usage: go run main.go [filename]")
        return
    }
    
    filename := os.Args[1]
    dataPath := "data.png"
    outputPath := "output.png"
    
    fmt.Printf("Reading target image %s...
", filename)
    img, err := readImage(filename)
    if err != nil {
        fmt.Println(err)
        return
    }
    
    fmt.Printf("Reading data image %s...
", dataPath)
    data, err := readData(dataPath)
    if err != nil {
        fmt.Println(err)
        return
    }
    
    fmt.Println("Hiding data...")
    newImg, err := hideData(img, data)
    if err != nil {
        fmt.Println(err)
        return
    }
    
    fmt.Printf("Saving image to %s...
", outputPath)
    err = saveImage(outputPath, newImg)
    if err != nil {
        fmt.Println(err)
        return
    }
    
    fmt.Println("Done!")
}

func readImage(path string) (image.Image, error) {
    f, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer f.Close()
    
    img, _, err := image.Decode(f)
    if err != nil {
        return nil, err
    }
    
    return img, nil
}

func readData(path string) ([]byte, error) {
    data, err := ioutil.ReadFile(path)
    if err != nil {
        return nil, err
    }
    
    return data, nil
}

func hideData(img image.Image, data []byte) (image.Image, error) {
    bounds := img.Bounds()
    
    newImg := image.NewRGBA(bounds)
    
    idx := 0    
    var r, g, b, a uint32
    
    for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
        for x := bounds.Min.X; x < bounds.Max.X; x++ {
            r, g, b, a = img.At(x, y).RGBA()
            if idx < len(data)*8 {
                bitIdx := idx % 8
                bits := uint32(data[idx/8])
                mask := uint32(0x00 << bitIdx)
                if bits&(1<<7-bitIdx) > 0 {
                    mask |= uint32(0x01 << bitIdx)
                }
                r = (r & 0xFFFE) | (mask & 0x01)
                g = (g & 0xFFFE) | ((mask >> 1) & 0x01)
                b = (b & 0xFFFE) | ((mask >> 2) & 0x01)
                a = (a & 0xFFFE) | ((mask >> 3) & 0x01)                
            }
            newImg.Set(x, y, color.RGBA64{uint16(r), uint16(g), uint16(b), uint16(a)})
            idx++
        }
    }
    
    return newImg, nil
}

func saveImage(path string, img image.Image) error {
    f, err := os.Create(path)
    if err != nil {
        return err
    }
    defer f.Close()
    
    err = png.Encode(f, img)
    if err != nil {
        return err
    }
    
    return nil
}

The above are the steps and code for Golang to implement image hiding technology. It should be noted that this image hiding technology does not completely guarantee data security, it is just an encryption method. If data privacy is to be protected more strictly, other encryption methods need to be considered.

Summary

As an efficient programming language, Golang has excellent image processing capabilities. In this article, we use Golang to implement image hiding technology, which can ensure data privacy to a certain extent. It is worth noting that this technology cannot fully guarantee data security, so in practical applications, more encryption methods are needed to protect data privacy.

The above is the detailed content of golang picture hide. For more information, please follow other related articles on the PHP Chinese website!