Compress size of image to 250kb using xamarin.forms without dependency service

Question

I\'m trying to compress image taken from camera to 250kb size in Xamarin.Forms. I found ways to do that in dependency service but I want it without dependency service (pure

Answer 1

It is a very complicated job since you would need a ton of knowledge about image processing.

Most importantly, re-inventing wheel is a bad move.

http://www.codeproject.com/Articles/83225/A-Simple-JPEG-Encoder-in-C

Take a look of the above code project which only tackles JPEG; not to say TIFF, GIF, BMP etc.

Image compression involves many complex mathematics transforms, like DCT and Huffman.

You will need a whole university semester to learn those basics.

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On the other hand, wisely utilizing platform support, you can complete the task within a minute.

BitmapEncoder in Windows Phone.

FileStream stream = new FileStream("new.jpg", FileMode.Create);
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.QualityLevel = 30;
encoder.Frames.Add(BitmapFrame.Create(image));
encoder.Save(stream);

Bitmap in Android

using (System.IO.Stream stream = System.IO.File.Create(targetFile))
{
    bitmap.Compress(Bitmap.CompressFormat.Jpeg, 30, stream);
}

UIImage in iOS

NSData data = image.AsJPEG(0.3);

Bitmap in .NET framework

ImageCodecInfo[] codecs = ImageCodecInfo.GetImageDecoders();
ImageCodecInfo codec = codecs.First(t => t.FormatID == ImageFormat.Jpeg.Guid);
EncoderParameters parameters = new EncoderParameters(1);
parameters.Param[0] = new EncoderParameter(Encoder.Quality, 30L);
bitmap.Save("output.jpg", codec, parameters);