Reading and writing binary images with streams

26 Sep 2023

In this blog post, we will explore how to read and write binary images using streams in different programming languages. Streams provide a convenient way to manipulate binary data without having to load the entire image into memory at once.

Let’s dive into the code examples in three popular programming languages: Python, Java, and C++.

Reading Binary Images

Python

import numpy as np

with open("binary_image.bin", "rb") as file:
    binary_data = file.read()
    binary_image = np.frombuffer(binary_data, dtype=np.uint8)

Java

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;

public class BinaryImageReader {
    public static void main(String[] args) {
        try (DataInputStream dis = new DataInputStream(new FileInputStream("binary_image.bin"))) {
            byte[] binaryData = new byte[(int)dis.length()];
            dis.readFully(binaryData);
            int[] binaryImage = new int[binaryData.length];
            
            for (int i = 0; i < binaryData.length; i++) {
                binaryImage[i] = binaryData[i] & 0xFF;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

C++

#include <iostream>
#include <fstream>
#include <vector>

int main() {
    std::ifstream file("binary_image.bin", std::ios::binary | std::ios::ate);
    std::streampos imageSize = file.tellg();
    file.seekg(0, std::ios::beg);

    std::vector<unsigned char> binaryData(imageSize);
    if (file.read(reinterpret_cast<char*>(binaryData.data()), imageSize)) {
        // Process binary image data
    }
    
    file.close();
}

Writing Binary Images

Python

import numpy as np

binary_image = np.array([0, 1, 1, 0, 1], dtype=np.uint8)

with open("binary_image.bin", "wb") as file:
    file.write(binary_image.tobytes())

Java

import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class BinaryImageWriter {
    public static void main(String[] args) {
        int[] binaryImage = {0, 1, 1, 0, 1};
        
        try (DataOutputStream dos = new DataOutputStream(new FileOutputStream("binary_image.bin"))) {
            for (int pixel : binaryImage) {
                dos.writeInt(pixel);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

C++

#include <iostream>
#include <fstream>
#include <vector>

int main() {
    std::vector<unsigned char> binaryImage = {0, 1, 1, 0, 1};
    
    std::ofstream file("binary_image.bin", std::ios::binary);
    file.write(reinterpret_cast<char*>(binaryImage.data()), binaryImage.size());
    
    file.close();
}

Reading and writing binary images using streams provides an efficient and memory-optimized way to work with large image datasets. With the code examples provided in Python, Java, and C++, you can now leverage streams to perform image processing tasks on binary images effectively.

#computerVision #binaryImages