Legacy ImageMagick Discussions Archive

Can you please tell me how can I convert a ppm image to a YUV NV12 format?

Let's say I have a ppm image with size 800X600, called sage_1.ppm, what to do to convert it to a yuv nv12 format?

Thanks. But I get an 'unexpected end of file error:
The original image Bretagne1.ppm from http://www.openjpeg.org/index.php?menu=samples. is 640X480.

$ mv Bretagne2.Cb temp.gray
$ convert -size 640x480 -resize 50% temp.gray ~/Downloads/Bretagne2-ds.Cb
convert: unexpected end-of-file `temp.gray ...

Thanks Glen for your reply.

I tried that with my sample image Bretagne1 from http://www.openjpeg.org/index.php?menu=samples.
It has even row and column.

But I get this error:
$ convert ~/Downloads/Bretagne1.ppm -interlace partition -colorspace YCbCr Bretagne2.ycbcr
$ convert -resize 50 ...

Thanks but it does not give me what I am looking for.

I am looking for what this does, but break it down in YCbCr instead of YUV:
convert ~/Downloads/Bretagne1.ppm -interlace partition Bretagne2.yuv

This is the output from the above comment. Each Y, U, V is smaller than the original image ...

Thanks a lot for your answer.

I get "save Y to a file, U to a file , V to a file" works.

But how can I save Y to a file , Cb to a file, Cr to a file?

I tried:
convert ~/Downloads/Bretagne1.ppm -interlace partition -colorspace YCbCr Bretagne2.yuv

does not work.

And I tried:
convert ~/Downloads ...

Thanks a lot for all your answers!

Thanks for the pointers.
I googled how to use 'interlace'.
From this http://www.chemie.fu-berlin.de/chemnet/use/suppl/imagemagick/www/convert.html, it seems like
it will create a interlaced GIF or progressive JPEG.

How can I save Y to a file, U to a file , V to a file?

Sorry that my question ...

Thanks for all the answers.

If I understanding correctly, PPM image can't be in YUV 422 format, it can only in RGB format.

My next question is , can I use IM to convert PPM's RBG format to YUV422 and save Y , U, V's data into different files?
i.e. the output image is not an image but 3 planes of Y ...

Hi,

I am trying to use imageMagick to convert a ppm image in RGB format to YUV422 format:
I am using Bretagne1 ppm from:
http://www.openjpeg.org/index.php?menu=samples

I tried:
convert ~/Downloads/Bretagne1.ppm -colorspace YCbCr ~/Downloads/Bretagne2.ppm
convert ~/Downloads/Bretagne1.ppm ...

Thanks. I get the image "tulips_yuv422_inter_planar_qcif.yuv " from http://www.sunrayimage.com/examples.html.

I find out the image is All in qcif format, 176x144.

so I tried using IM by "display -size 176x144 -colorspace YUV tulips_yuv422_inter_planar_qcif.yuv "

It seems to me the 'red' part of ...

Hi,

I am running ImageMagick on ubuntu.
How can I use it to optn a yuv image?

I tried:

display ~/Downloads/tulips_yuv422_inter_planar_qcif.yuv
display: must specify image size `~/Downloads/tulips_yuv422_inter_planar_qcif.yuv' @ error/yuv.c/ReadYUVImage/145.

How can I find out the size of a ...