Tutorial: How to Update BMP Image Properties Without Storage

Learning Objectives

In this tutorial, you’ll learn how to:

Update BMP image properties without first uploading to cloud storage
Modify color depth (bits per pixel) and resolution directly
Process BMP images by sending them in the request body
Save processed images either locally or to cloud storage
Work with Device Independent Bitmap (DIB) file format

Prerequisites

Before starting this tutorial, make sure you have:

An Aspose Cloud account (sign up at dashboard.aspose.cloud)
Your Client ID and Client Secret from the Aspose Cloud dashboard
A local BMP image file for testing
Basic knowledge of REST API concepts
Familiarity with either cURL, .NET, or Java for the examples

Understanding Direct Image Processing

Sometimes you may want to process images without first uploading them to cloud storage. This approach is beneficial when:

You need to process images one time only
You’re working with images that don’t need to be stored
You want to simplify your workflow by eliminating the upload step

Aspose.Imaging Cloud API supports direct image processing by allowing you to send the image in the request body.

Tutorial Steps

Step 1: Prepare Your Authentication

Every API request to Aspose.Imaging Cloud requires authentication. We’ll use the OAuth 2.0 client credentials flow to obtain a JWT token:

curl -v "https://api.aspose.cloud/connect/token" \
-X POST \
-d 'grant_type=client_credentials&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET' \
-H "Content-Type: application/x-www-form-urlencoded" \
-H "Accept: application/json"

Save the JWT token from the response for use in subsequent requests.

Step 2: Update BMP Image Properties Without Storage

Instead of uploading the image to cloud storage first, we’ll send it directly in the request:

curl -v "https://api.aspose.cloud/v3/imaging/bmp?bitsPerPixel=32&horizontalResolution=300&verticalResolution=300" \
-X POST \
-T "path/to/your/local/WaterMark.bmp" \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-o WaterMark_updated.bmp

In this request:

The HTTP method is POST (not GET as in the storage-based approach)
The BMP image file is sent in the request body using the -T option
The same query parameters are used to specify the desired property changes
The updated image is saved to a local file named “WaterMark_updated.bmp”

Parameters Explained

Parameter	Description	Possible Values
bitsPerPixel	Color depth in bits per pixel	1, 4, 8, 16, 24, 32
horizontalResolution	Horizontal pixel density in DPI	Any positive number (common: 72, 96, 150, 300, 600)
verticalResolution	Vertical pixel density in DPI	Any positive number (common: 72, 96, 150, 300, 600)
outPath	Optional parameter to save the result to cloud storage	Path in cloud storage (e.g., “updated/WaterMark.bmp”)

Try it yourself

Modify the cURL command to use your own BMP image
Try different combinations of the parameters
Add the outPath parameter to save the result directly to cloud storage

Step 3: Saving the Result to Cloud Storage

If you want to save the processed image to cloud storage instead of downloading it, you can add the outPath parameter:

curl -v "https://api.aspose.cloud/v3/imaging/bmp?bitsPerPixel=32&horizontalResolution=300&verticalResolution=300&outPath=updated/WaterMark.bmp" \
-X POST \
-T "path/to/your/local/WaterMark.bmp" \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN"

With this approach:

The outPath parameter specifies where to save the result in cloud storage
No response body is returned since the image is saved to the cloud
You can verify the result by checking the specified path in your cloud storage

Step 4: Using the SDK for Easier Integration

For a more programmatic approach, you can use the Aspose.Imaging Cloud SDKs. Here are examples for both .NET and Java:

.NET SDK Example

// Update parameters of BMP image without storage
public static void UpdateBmpImagePropertiesWithoutStorage()
{
    // Create Imaging API client
    var imagingApi = new ImagingApi("YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET");

    try
    {
        // Prepare parameters
        int bitsPerPixel = 32;
        double horizontalResolution = 300;
        double verticalResolution = 300;
        string outPath = null; // Set to null to get the result in the response, or specify a path to save in the cloud
        
        // Read image from file
        using var imageStream = new FileStream("WaterMark.bmp", FileMode.Open);
        
        Console.WriteLine("Updating BMP image properties without storage...");
        
        // Create request with image from local file
        var request = new CreateModifiedBmpRequest(
            imageStream,
            bitsPerPixel,
            horizontalResolution,
            verticalResolution,
            outPath
        );
        
        // Get updated image as stream
        using var updatedImageStream = imagingApi.CreateModifiedBmp(request);
        
        // Save updated image to local file
        using var fileStream = new FileStream("WaterMark_updated.bmp", FileMode.Create);
        updatedImageStream.CopyTo(fileStream);
        
        Console.WriteLine("Updated BMP image saved to WaterMark_updated.bmp");
    }
    catch (Exception e)
    {
        Console.WriteLine("Error: " + e.Message);
    }
}

Java SDK Example

// Update parameters of BMP image without storage
public static void updateBmpImagePropertiesWithoutStorage() {
    try {
        // Create Imaging API client
        ImagingApi imagingApi = new ImagingApi("YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET");

        // Prepare parameters
        Integer bitsPerPixel = 32;
        Double horizontalResolution = 300.0;
        Double verticalResolution = 300.0;
        String outPath = null; // Set to null to get the result in the response, or specify a path to save in the cloud
        
        // Read image from file
        byte[] imageData = Files.readAllBytes(Paths.get("WaterMark.bmp"));
        
        System.out.println("Updating BMP image properties without storage...");
        
        // Create request with image from local file
        CreateModifiedBmpRequest request = new CreateModifiedBmpRequest(
            imageData,
            bitsPerPixel,
            horizontalResolution,
            verticalResolution,
            outPath
        );
        
        // Get updated image
        byte[] updatedImage = imagingApi.createModifiedBmp(request);
        
        // Save updated image to local file
        try (OutputStream outputStream = new FileOutputStream("WaterMark_updated.bmp")) {
            outputStream.write(updatedImage);
        }
        
        System.out.println("Updated BMP image saved to WaterMark_updated.bmp");
    } catch (Exception e) {
        System.out.println("Error: " + e.getMessage());
    }
}

Step 5: Saving Directly to Cloud Storage Using SDK

If you want to save the result directly to cloud storage when using the SDK, you can specify the outPath parameter:

.NET SDK Example

// Save updated BMP image directly to cloud storage
public static void SaveUpdatedBmpToCloudStorage()
{
    // Create Imaging API client
    var imagingApi = new ImagingApi("YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET");

    try
    {
        // Prepare parameters
        int bitsPerPixel = 32;
        double horizontalResolution = 300;
        double verticalResolution = 300;
        string outPath = "updated/WaterMark.bmp"; // Specify path in cloud storage
        
        // Read image from file
        using var imageStream = new FileStream("WaterMark.bmp", FileMode.Open);
        
        Console.WriteLine("Updating BMP image and saving directly to cloud storage...");
        
        // Create request with image from local file and outPath parameter
        var request = new CreateModifiedBmpRequest(
            imageStream,
            bitsPerPixel,
            horizontalResolution,
            verticalResolution,
            outPath
        );
        
        // Process the image and save to cloud storage
        imagingApi.CreateModifiedBmp(request);
        
        Console.WriteLine("Updated BMP image saved to cloud storage at: " + outPath);
    }
    catch (Exception e)
    {
        Console.WriteLine("Error: " + e.Message);
    }
}

Practical Applications

Here are some practical scenarios where updating BMP properties without storage is useful:

Image Optimization: Quickly adjust color depth to reduce file size before using the image in a web application
Print Preparation: Update the resolution of images to match print requirements without storing intermediates
Batch Processing: Process multiple BMP files in sequence, applying the same property changes to each
On-the-fly Conversion: Update properties as part of a conversion pipeline where intermediate results don’t need to be stored

Troubleshooting Tips

File Format Errors: Ensure you’re providing a valid BMP file. The API will return an error if the input isn’t a proper BMP image.
Authentication Issues: Check that your JWT token is valid and not expired.
Parameter Validation: The bitsPerPixel parameter must be one of the supported values (1, 4, 8, 16, 24, 32).
Storage Path: If using outPath, ensure the target folder exists in your cloud storage or use a path that doesn’t require pre-existing folders.

What You’ve Learned

In this tutorial, you’ve learned:

How to update BMP image properties without first uploading to cloud storage
How to send images directly in the request body for processing
Options for saving the processed image (locally or to cloud storage)
Implementation using both direct REST API calls and SDKs
Practical applications for this approach in real-world scenarios

Further Practice

To reinforce your learning:

Create a script that processes multiple BMP images with different property settings
Build a simple web application that allows users to adjust BMP properties on-the-fly
Compare the performance between the storage-based approach and the direct approach
Experiment with changing color depth and observe the visual differences and file size impacts

Next Tutorial

Continue your learning journey with Tutorial: How to Update GIF Image Properties to learn techniques for working with animated image formats.

Helpful Resources

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