C#•2w ago

BAD IMAGE QUALITY (Bitmap)

Making a functionnality to add image to a page, but when i save it the quality is just horrible. It feel like on screen the image difference are the same, but there is very a big quality difference. Is there a way to make it look way better? Code :

using (Bitmap bmp = new Bitmap(pageImage.Width, pageImage.Height))
{
    pageImage.DrawToBitmap(bmp, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    bmp.Save(originalLocation);
}

using (Bitmap bmp = new Bitmap(pageImage.Width, pageImage.Height))
{
    pageImage.DrawToBitmap(bmp, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    bmp.Save(originalLocation);
}

7 Replies

Sehra•2w ago

some more context would help. what is pageImage?

Silme94OP•2w ago

pageImage is the PictureBox

Silme94OP•2w ago

Sehra•2w ago

maybe need to tweak the interpolation mode, or scale it properly when switching from 96 dpi screen to 300 dpi pdf

Salman•2w ago

maybe try this :

RenderOptions.SetBitmapScalingMode(image, BitmapScalingMode.HighQuality);

RenderOptions.SetBitmapScalingMode(image, BitmapScalingMode.HighQuality);

it helped me to make the image quality better back then

Lyrcaxis•2w ago

For reference I stopped having to deal with Bitmap in favour of storing everything as bytes:

public static byte[] GetGraphic(string path) {
    using var m = new MemoryStream();
    var image = System.Drawing.Image.FromFile(path);
    image.Save(m, image.RawFormat);
    return m.ToArray();
}

public static byte[] GetGraphic(string path) {
    using var m = new MemoryStream();
    var image = System.Drawing.Image.FromFile(path);
    image.Save(m, image.RawFormat);
    return m.ToArray();
}

So something like: ImageBytes = Utils.GetGraphic(path); and rendering via <Image Source="{Binding ImageBytes}"/> ok now I see you're querying about saving it, not loading it. You can do the same:

using var m = new MemoryStream();
image.Save(memoryStream, ImageFormat.Png);
return m.ToArray();

using var m = new MemoryStream();
image.Save(memoryStream, ImageFormat.Png);
return m.ToArray();

Then System.IO.File.WriteAllBytes.

Silme94OP•2w ago

@Salman @Sehra still the same quality...

using (MemoryStream memoryStream = new MemoryStream())
{
    Image controlImage = new Bitmap(pageImage.Width, pageImage.Height);

    using (Graphics graphics = Graphics.FromImage(controlImage))
    {
        graphics.Clear(Color.White);
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

        pageImage.DrawToBitmap((Bitmap)controlImage, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    }

    controlImage.Save(memoryStream, ImageFormat.Png);
    File.WriteAllBytes(originalLocation, memoryStream.ToArray());
}

using (MemoryStream memoryStream = new MemoryStream())
{
    Image controlImage = new Bitmap(pageImage.Width, pageImage.Height);

    using (Graphics graphics = Graphics.FromImage(controlImage))
    {
        graphics.Clear(Color.White);
        graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
        graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;

        pageImage.DrawToBitmap((Bitmap)controlImage, new Rectangle(0, 0, pageImage.Width, pageImage.Height));
    }

    controlImage.Save(memoryStream, ImageFormat.Png);
    File.WriteAllBytes(originalLocation, memoryStream.ToArray());
}

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BAD IMAGE QUALITY (Bitmap)

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