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Adjust Brightness

Adjust the brightness of an image to make it lighter or darker.

POST /api/image/brightness

Request Parameters

Parameter Type Required Description
file File Yes The image file to adjust. Supported formats: JPEG, PNG, WebP, BMP, TIFF.
factor Float No The brightness adjustment factor. Values > 1.0 increase brightness, values < 1.0 decrease brightness. Range: 0.1-3.0. Default: 1.0.

Response

Returns the brightness-adjusted image in the same format as the input file.

Example Request

    curl -X POST "https://oyyi.xyz/api/image/brightness" \
  -H "accept: application/json" \
  -H "Content-Type: multipart/form-data" \
  -F "file=@image.jpg" \
  -F "factor=1.2" \
  --output brightened.jpg

Example with Python

    import requests

url = "https://oyyi.xyz/api/image/brightness"

files = {
    'file': open('image.jpg', 'rb')
}

data = {
    'factor': 1.2
}

response = requests.post(url, files=files, data=data)

# Save the brightened image
with open('brightened.jpg', 'wb') as f:
    f.write(response.content)

Example with JavaScript

    // Using fetch API
const formData = new FormData();
formData.append('file', fileInput.files[0]);
formData.append('factor', '1.2');

fetch('https://oyyi.xyz/api/image/brightness', {
  method: 'POST',
  body: formData
})
.then(response => response.blob())
.then(blob => {
  // Create a URL for the blob
  const url = URL.createObjectURL(blob);

  // Create a link to download the image
  const a = document.createElement('a');
  a.href = url;
  a.download = 'brightened.jpg';
  a.click();

  // Clean up by revoking the URL
  URL.revokeObjectURL(url);
})
.catch(error => console.error('Error:', error));

Brightness Factor Examples

Low Factor (0.1-0.9)

Darkens the image

Normal Factor (1.0)

No change to brightness

High Factor (1.1-3.0)

Brightens the image

How It Works

Brightness adjustment works by multiplying each pixel's RGB values by the brightness factor:

  • For each pixel, the R, G, and B values are multiplied by the brightness factor.
  • Values are clamped to the valid range (0-255) to prevent overflow.

Error Responses

Status Code Description
400 Bad request. Missing required parameters, invalid factor value, or invalid file format.
413 Payload too large. The file size exceeds the maximum allowed limit.
500 Internal server error. Something went wrong on the server.

Notes

  • Very high brightness factors may result in loss of detail in bright areas due to clipping.
  • Very low brightness factors may result in loss of detail in dark areas.
  • For subtle brightening, use values between 1.1 and 1.5.
  • For dramatic brightening, use values between 1.5 and 3.0.
  • To darken an image, use values between 0.1 and 0.9.
  • The maximum file size allowed is 10MB.
  • This operation preserves the alpha channel (transparency) if present in the original image.

Use Cases

  • Correcting underexposed images
  • Enhancing details in dark areas
  • Creating high-key or low-key effects
  • Preparing images for print where brightness adjustments may be needed
  • Darkening overexposed images
  • Creating mood or atmosphere in images
Contrast Threshold