Thumbnail Image Grainy

I found this link to create a thumbnail image.
http://forums.asp.net/t/739822.aspx

But the thumbnail image looks grainy.
If I take the same image, resample it in corel photopaint at 72dpi, the
image is nice and small and not grainy at all ( sharp ).

I was wondering if there is anything else that can be done to a jpg as you
are compressing it down to a smaller jpg, so you do not end up with a grainy
image.

Thanks,

Miro

Miro

I found this - but I cant seem to convert it to vb.

// Prepare for a controlled-quality JPEG
exportImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
Encoder jpegEncoder = Encoder.Quality;
EncoderParameters jpegEncoderParameters = new EncoderParameters(1);
EncoderParameter jpegEncoderQuality = new EncoderParameter(jpegEncoder,
jpegQuality);
jpegEncoderParameters.Param[0] = jpegEncoderQuality;string thumbnailPath;
// some path to save your JPEG to
thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters);



"Miro" <> wrote in message
news:...
>I found this link to create a thumbnail image.
> http://forums.asp.net/t/739822.aspx
>
> But the thumbnail image looks grainy.
> If I take the same image, resample it in corel photopaint at 72dpi, the
> image is nice and small and not grainy at all ( sharp ).
>
> I was wondering if there is anything else that can be done to a jpg as you
> are compressing it down to a smaller jpg, so you do not end up with a
> grainy image.
>
> Thanks,
>
> Miro

Miro

On Nov 6, 9:06*pm, "Miro" <m...@beero.com> wrote:
> I found this - but I cant seem to convert it to vb.
>
> // Prepare for a controlled-quality JPEG
> exportImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
> Encoder jpegEncoder = Encoder.Quality;
> EncoderParameters jpegEncoderParameters = new EncoderParameters(1);
> EncoderParameter jpegEncoderQuality = new EncoderParameter(jpegEncoder,
> jpegQuality);
> jpegEncoderParameters.Param[0] = jpegEncoderQuality;string thumbnailPath;
> // some path to save your JPEG to
> thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters);
>
> "Miro" <m...@beero.com> wrote in message
>
> news:...
>
>
>
> >I found this link to create a thumbnail image.
> >http://forums.asp.net/t/739822.aspx
>
> > But the thumbnail image looks grainy.
> > If I take the same image, resample it in corel photopaint at 72dpi, the
> > image is nice and small and not grainy at all ( sharp ).
>
> > I was wondering if there is anything else that can be done to a jpg as you
> > are compressing it down to a smaller jpg, so you do not end up with a
> > grainy image.
>
> > Thanks,
>
> > Miro

' Prepare for a controlled-quality JPEG
Dim jpegCodec As exportImageCodecInfo = GetEncoderInfo("image/jpeg")
Dim jpegEncoder As Encoder = Encoder.Quality
Dim jpegEncoderParameters As New EncoderParameters(1)
Dim jpegEncoderQuality As New EncoderParameter(jpegEncoder,
jpegQuality)
jpegEncoderParameters.Param(0) = jpegEncoderQuality
Dim thumbnailPath As String
' some path to save your JPEG to
thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters)

Alexey Smirnov

Thanks Alexy,

this got me on the right track but my image is still more grainy than if I
do it in something like corel photopaint.

Here is my code below. Perhaps I have a logical error somehwere ?
Take note of the 1000L ...if I put 100L or anything higher it does not get
better, but a value of 0 is really really grainy...so I was hoping this was
some kind of a weird calculated value.


Private Sub generateThumbnail(ByVal filepath As String, ByVal FileName
As String)

'Create a new Bitmap Image loading from location of origional file
'Dim bm As Bitmap = System.Drawing.Image.FromFile(filepath &
FileName)
Dim jpg As System.Drawing.Image =
System.Drawing.Image.FromFile(filepath & FileName)

'Declare Thumbnails Height and Width
Dim newWidth As Integer = 125
'Dim newHeight As Integer = (newWidth / bm.Width) * bm.Height
Dim newHeight As Integer = (newWidth / jpg.Width) * jpg.Height
Dim resizedBMP As Bitmap = New Bitmap(jpg, newWidth, newHeight)



' Prepare for a controlled-quality JPEG
Dim jpegCodec As ImageCodecInfo = GetEncoderInfo("image/jpeg")
Dim jpegEncoder As Encoder = Encoder.Quality
Dim jpegEncoderParameters As New EncoderParameters(1)
Dim jpegEncoderQuality As New EncoderParameter(jpegEncoder, 1000L)
jpegEncoderParameters.Param(0) = jpegEncoderQuality
'Dim thumbnailPath As String
' some path to save your JPEG to
Dim newStrFileName As String = filepath & "ThumbNails/" & FileName
resizedBMP.Save(newStrFileName, jpegCodec, jpegEncoderParameters)
End Sub

Private Function GetEncoderInfo(ByVal mimeType As String) _
As ImageCodecInfo
Dim j As Integer
Dim encoders As ImageCodecInfo()
encoders = ImageCodecInfo.GetImageEncoders()
For j = 0 To encoders.Length
If encoders(j).MimeType = mimeType Then
Return encoders(j)
End If
Next j
Return Nothing
End Function


Miro

"Alexey Smirnov" <> wrote in message
news:7d5661af-9947-45df-b21e-...
On Nov 6, 9:06 pm, "Miro" <m...@beero.com> wrote:
> I found this - but I cant seem to convert it to vb.
>
> // Prepare for a controlled-quality JPEG
> exportImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
> Encoder jpegEncoder = Encoder.Quality;
> EncoderParameters jpegEncoderParameters = new EncoderParameters(1);
> EncoderParameter jpegEncoderQuality = new EncoderParameter(jpegEncoder,
> jpegQuality);
> jpegEncoderParameters.Param[0] = jpegEncoderQuality;string thumbnailPath;
> // some path to save your JPEG to
> thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters);
>
> "Miro" <m...@beero.com> wrote in message
>
> news:...
>
>
>
> >I found this link to create a thumbnail image.
> >http://forums.asp.net/t/739822.aspx
>
> > But the thumbnail image looks grainy.
> > If I take the same image, resample it in corel photopaint at 72dpi, the
> > image is nice and small and not grainy at all ( sharp ).
>
> > I was wondering if there is anything else that can be done to a jpg as
> > you
> > are compressing it down to a smaller jpg, so you do not end up with a
> > grainy image.
>
> > Thanks,
>
> > Miro

' Prepare for a controlled-quality JPEG
Dim jpegCodec As exportImageCodecInfo = GetEncoderInfo("image/jpeg")
Dim jpegEncoder As Encoder = Encoder.Quality
Dim jpegEncoderParameters As New EncoderParameters(1)
Dim jpegEncoderQuality As New EncoderParameter(jpegEncoder,
jpegQuality)
jpegEncoderParameters.Param(0) = jpegEncoderQuality
Dim thumbnailPath As String
' some path to save your JPEG to
thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters)

Miro

Rewrote it a bit...but still grainy - found some differnet code- hoping that
would work.

Dim bm As Bitmap = System.Drawing.Image.FromFile(filepath & FileName)
Dim newWidth As Integer = 125
Dim newHeight As Integer = (newWidth / bm.Width) * bm.Height
Dim resizedBMP As Bitmap = New Bitmap(bm, newWidth, newHeight)


Dim info As ImageCodecInfo = ImageCodecInfo.GetImageEncoders(1)
Dim Params As EncoderParameters = New EncoderParameters(1)
Params.Param(0) = New
EncoderParameter(System.Drawing.Imaging.Encoder.Qu ality, 100L)
Dim newStrFileName As String = filepath & "ThumbNails/" & FileName
resizedBMP.Save(newStrFileName, info, Params)


"Miro" <> wrote in message
news:...
> Thanks Alexy,
>
> this got me on the right track but my image is still more grainy than if I
> do it in something like corel photopaint.
>
> Here is my code below. Perhaps I have a logical error somehwere ?
> Take note of the 1000L ...if I put 100L or anything higher it does not get
> better, but a value of 0 is really really grainy...so I was hoping this
> was some kind of a weird calculated value.
>
>
> Private Sub generateThumbnail(ByVal filepath As String, ByVal FileName
> As String)
>
> 'Create a new Bitmap Image loading from location of origional file
> 'Dim bm As Bitmap = System.Drawing.Image.FromFile(filepath &
> FileName)
> Dim jpg As System.Drawing.Image =
> System.Drawing.Image.FromFile(filepath & FileName)
>
> 'Declare Thumbnails Height and Width
> Dim newWidth As Integer = 125
> 'Dim newHeight As Integer = (newWidth / bm.Width) * bm.Height
> Dim newHeight As Integer = (newWidth / jpg.Width) * jpg.Height
> Dim resizedBMP As Bitmap = New Bitmap(jpg, newWidth, newHeight)
>
>
>
> ' Prepare for a controlled-quality JPEG
> Dim jpegCodec As ImageCodecInfo = GetEncoderInfo("image/jpeg")
> Dim jpegEncoder As Encoder = Encoder.Quality
> Dim jpegEncoderParameters As New EncoderParameters(1)
> Dim jpegEncoderQuality As New EncoderParameter(jpegEncoder, 1000L)
> jpegEncoderParameters.Param(0) = jpegEncoderQuality
> 'Dim thumbnailPath As String
> ' some path to save your JPEG to
> Dim newStrFileName As String = filepath & "ThumbNails/" & FileName
> resizedBMP.Save(newStrFileName, jpegCodec, jpegEncoderParameters)
> End Sub
>
> Private Function GetEncoderInfo(ByVal mimeType As String) _
> As ImageCodecInfo
> Dim j As Integer
> Dim encoders As ImageCodecInfo()
> encoders = ImageCodecInfo.GetImageEncoders()
> For j = 0 To encoders.Length
> If encoders(j).MimeType = mimeType Then
> Return encoders(j)
> End If
> Next j
> Return Nothing
> End Function
>
>
> Miro
>
> "Alexey Smirnov" <> wrote in message
> news:7d5661af-9947-45df-b21e-...
> On Nov 6, 9:06 pm, "Miro" <m...@beero.com> wrote:
>> I found this - but I cant seem to convert it to vb.
>>
>> // Prepare for a controlled-quality JPEG
>> exportImageCodecInfo jpegCodec = GetEncoderInfo("image/jpeg");
>> Encoder jpegEncoder = Encoder.Quality;
>> EncoderParameters jpegEncoderParameters = new EncoderParameters(1);
>> EncoderParameter jpegEncoderQuality = new EncoderParameter(jpegEncoder,
>> jpegQuality);
>> jpegEncoderParameters.Param[0] = jpegEncoderQuality;string thumbnailPath;
>> // some path to save your JPEG to
>> thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters);
>>
>> "Miro" <m...@beero.com> wrote in message
>>
>> news:...
>>
>>
>>
>> >I found this link to create a thumbnail image.
>> >http://forums.asp.net/t/739822.aspx
>>
>> > But the thumbnail image looks grainy.
>> > If I take the same image, resample it in corel photopaint at 72dpi, the
>> > image is nice and small and not grainy at all ( sharp ).
>>
>> > I was wondering if there is anything else that can be done to a jpg as
>> > you
>> > are compressing it down to a smaller jpg, so you do not end up with a
>> > grainy image.
>>
>> > Thanks,
>>
>> > Miro
>
> ' Prepare for a controlled-quality JPEG
> Dim jpegCodec As exportImageCodecInfo = GetEncoderInfo("image/jpeg")
> Dim jpegEncoder As Encoder = Encoder.Quality
> Dim jpegEncoderParameters As New EncoderParameters(1)
> Dim jpegEncoderQuality As New EncoderParameter(jpegEncoder,
> jpegQuality)
> jpegEncoderParameters.Param(0) = jpegEncoderQuality
> Dim thumbnailPath As String
> ' some path to save your JPEG to
> thumbnail.Save(thumbnailPath, jpegCodec, jpegEncoderParameters)

Miro

Alexey Smirnov schrieb:
> On Nov 6, 9:06 pm, "Miro" <m...@beero.com> wrote:
>> I found this - but I cant seem to convert it to vb.

I assume that commercial products contain more evolved compression
algorithms than the .NET Framework's default JPEG encoder. Adobe
Photoshop, for example, provides a better quality/file size ratio than
the .NET Framework's JPEG encoder too. The encoder used by GIMP is
worse than Photoshop's encoder.

Depending on the type of images you may want to consider using the PNG
format instead of JPEG (it's more suitable for screenshots, for example).

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

Herfried K. Wagner [MVP]