SKImage.Encode in Bmp returns null

When trying to encode an image in Bmp, it always returns null.

I tried using different values for the quality from 0 to 100, knowing that anyway it does not make sense to have a quality in bmp, I actually thought it would just ignore it.

Here’s a sample that returns null.

var bitmap = SKBitmap.Decode(File.OpenRead(filename));
var image = SKImage.FromBitmap(bitmap);
var data = image.Encode(SKEncodedImageFormat.Bmp, 100); // null

Any idea how to make it work? I would like to avoid using the Bitmap.Bytes as the goal is to be able to also use other encoding format.

Thanks

Issue Analytics

State:
Created 6 years ago
Comments:9 (4 by maintainers)

Top GitHub Comments

4reactions

dsorondacommented, Feb 4, 2020

I just had issue where I needed to decode Webp image using SkiaSharp and convert it to Bmp format. Since SkiaSharp Encode is not supported I used BmpSharp as workaround. Maybe someone will find this useful (I almost created new issue for this.)

if (!(outputImage.BytesPerPixel == 3 || outputImage.BytesPerPixel == 4))
	throw new Exception( $"Unsupported Bits per image ({outputImage.BytesPerPixel}) for BmpSharp" );

var bitsPerPixel = outputImage.BytesPerPixel == 4 ? BmpSharp.BitsPerPixelEnum.RGBA32 : BmpSharp.BitsPerPixelEnum.RGB24;
var bmp = new BmpSharp.Bitmap( outputImage.Width, outputImage.Height, outputImage.Bytes, bitsPerPixel );
return bmp.GetBmpBytes(flipped:true);

Disclaimer : I’m author of BmpSharp

1reaction

ThmXcommented, Jun 27, 2017

I just saw the answer from Hal Canary. So I’m gonna use PNG instead. Even though the problem is not solved for BMP, I have a pretty good solution instead.

Thanks a lot for your inquiry.

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