> 1.Any standard method or algorithms which can do upscaling and
> downscaling the image..Pls suggest the link and the method and its
> equation..
It should be somewhat like the conventional signal processing for 1-D
signal, upsampling then filtering off some images; anti-alias
filtering then downsampling. And 2D filters should be used in
filtering process.
> 2.And also suggest do i need to use cascaded version of FIR filter or
> 2D FIR filter or polyphase FIR filter...Which one is most recommended
> as per the standard method.
>
> 3.Can i use a 2D -FIR filter for both upscaling and downscaling a
> image without zero padding?
> Pls share u r views with to proceed further..
>
> regards,
> raj
Reply by ●October 16, 20082008-10-16
On Oct 15, 5:07�am, raj <rajesh.o...@gmail.com> wrote:
> Hai,
>
> I am new to DSP.I have to do upscaling and downscaling of a image and
> implemented in FPGA.I referred resources and understood the bilinear
> method with FIR filter used for this..
>
> I knew about the basic FIR filter.I want to know the following:
>
> 1.Any standard method or algorithms which can do upscaling and
> downscaling the image..Pls suggest the link and the method and its
> equation..
>
> 2.And also suggest do i need to use cascaded version of FIR filter or
> 2D FIR filter or polyphase FIR filter...Which one is most recommended
> as per the standard method.
>
> 3.Can i use a 2D -FIR filter for both upscaling and downscaling a
> image without zero padding?
>
> Pls share u r views with to proceed further..
>
> regards,
> raj
There are a myriad ways to resample an image. Common approaches use
bilinear or bicubic interpolation. An old but coarse way is to use the
nearest neighbor. You can even use a sin(x)/x interpolation. There are
a host of computer graphics books that cover these common algorithms.
Try a visit to your university library and look up image processing.
Clay
Reply by dbell●October 16, 20082008-10-16
On Oct 15, 5:07�am, raj <rajesh.o...@gmail.com> wrote:
> Hai,
>
> I am new to DSP.I have to do upscaling and downscaling of a image and
> implemented in FPGA.I referred resources and understood the bilinear
> method with FIR filter used for this..
>
> I knew about the basic FIR filter.I want to know the following:
>
> 1.Any standard method or algorithms which can do upscaling and
> downscaling the image..Pls suggest the link and the method and its
> equation..
>
> 2.And also suggest do i need to use cascaded version of FIR filter or
> 2D FIR filter or polyphase FIR filter...Which one is most recommended
> as per the standard method.
>
> 3.Can i use a 2D -FIR filter for both upscaling and downscaling a
> image without zero padding?
>
> Pls share u r views with to proceed further..
>
> regards,
> raj
The solution to your problem is to study or hire someone who did.
Dirk
Reply by raj●October 15, 20082008-10-15
Hai,
I am new to DSP.I have to do upscaling and downscaling of a image and
implemented in FPGA.I referred resources and understood the bilinear
method with FIR filter used for this..
I knew about the basic FIR filter.I want to know the following:
1.Any standard method or algorithms which can do upscaling and
downscaling the image..Pls suggest the link and the method and its
equation..
2.And also suggest do i need to use cascaded version of FIR filter or
2D FIR filter or polyphase FIR filter...Which one is most recommended
as per the standard method.
3.Can i use a 2D -FIR filter for both upscaling and downscaling a
image without zero padding?
Pls share u r views with to proceed further..
regards,
raj