.NET Web アプリでリアルタイムの画像変換を実施する方法

[HttpPost("convert")]
public IActionResult ConvertImage(IFormFile file, [FromQuery] string format = "jpeg")
{
    if (file == null || file.Length == 0)
    {
        return BadRequest("No file uploaded.");
    }

    try
    {
        using (var stream = file.OpenReadStream())
        using (var image = Image.Load(stream))
        {
            var options = GetConversionOptions(format);
            string outputPath = Path.Combine("wwwroot/converted", $"{Guid.NewGuid()}.{format}");

            image.Save(outputPath, options);

            return Ok($"Converted image saved at: {outputPath}");
        }
    }
    catch (Exception ex)
    {
        return StatusCode(500, $"An error occurred: {ex.Message}");
    }
}

private ImageOptionsBase GetConversionOptions(string format)
{
    return format.ToLower() switch
    {
        "jpeg" => new JpegOptions { Quality = 80 },
        "png" => new PngOptions { CompressionLevel = 9 },
        "webp" => new WebPOptions { Quality = 75 },
        _ => throw new NotSupportedException($"Format {format} is not supported.")
    };
}