Databases
StackOverflow2013
Postsdbo
POGhost-borders ('ringing') when resizing in GDI+
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POGhost-borders ('ringing') when resizing in GDI+
    primarykey
    data
    text
    <p>What happens (only noticeable on certain images) is I will see a 1 pixel white border that is inset one pixel. It seems to happen in areas that are light but not white (e.g. the sky). It is similar to when something is oversharpened and a ghost border can be seen next to high contrast edges.</p> <p>Here is the repro code that reproduces it perfectly. I'm using all the highest quality settings for scaling.</p> <pre><code>ImageCodecInfo encoder = null; EncoderParameters encoderParams = null; foreach (ImageCodecInfo codec in ImageCodecInfo.GetImageEncoders()) { if (codec.MimeType == "image/jpeg") { encoder = codec; // use highest quality compression settings encoderParams = new EncoderParameters(1); encoderParams.Param[0] = new EncoderParameter(Encoder.Quality, 100L); break; } } using (Bitmap input = (Bitmap)Bitmap.FromFile(inputPath, true)) { // shrink by multiple of 2 Rectangle rect = new Rectangle(0, 0, input.Width/32, input.Height/32); using (Bitmap output = new Bitmap(rect.Width, rect.Height)) { using (Graphics g = Graphics.FromImage(output)) { // use highest quality settings (updated per Mark Ransom's answer) g.CompositingMode = CompositingMode.SourceCopy; g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.PixelOffsetMode = PixelOffsetMode.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.DrawImage(input, rect); } output.Save(outputPath, encoder, encoderParams); } } </code></pre> <p>Any ideas? I'm completely baffled. I've read through a ton of questions/answers and none of them seem to affect my situation.</p> <hr> <p><strong>Edit</strong>:</p> <p>This is an example <em>before</em> image: <a href="http://img14.imageshack.us/img14/4174/mg1647.jpg" rel="noreferrer">http://img14.imageshack.us/img14/4174/mg1647.jpg</a></p> <p>This is an example <em>after</em> image: <a href="http://img64.imageshack.us/img64/3156/afterringing.jpg" rel="noreferrer">http://img64.imageshack.us/img64/3156/afterringing.jpg</a></p> <p>It is more pronounced with the original files (before the hosting service "optimizes" them), but you can see in the sky a lighter band one-pixel in on the smaller image.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USmckamey
    1. USmckamey
    plurals
    1. PL
      singulars
      1. LTLinked
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. US9dan
      1. VTFavorite
    1. COI've read your description a little more carefully, and what you're describing is called "ringing". It can show up right at the edge or a very short distance from it. I can't see anything obvious in your code that would cause it, though. Sample images before/after might help.
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. USMark Ransom
    2. COYeah it is as if it is doing a sharpening algorithm which tries to look at the values of pixels beyond the edge of the image. I am trying to find a good place to post the before/after images.
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. USmckamey
    3. COThat sample *after* image doesn't quite show it as pronounced as I am seeing it in my application but you can still tell it is not right.
      singulars
      1. POGhost-borders ('ringing') when resizing in GDI+
      1. USmckamey
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload