How to conserve the size of the file convert from tif to ppm

[yarrow]

Hi, All,

I use nconvert to convert tif files to ppm. The size of my tif files are about
25M each. When i convert it to ppm, It becomes 75M each. The command
i use is:

nconvert -in tiff -ctype grey -colors 256 -out ppm -truecolors 1.tif

I wander is there any way to preserve the size of the tif file. I want 25M
ppm, not 75M. It is too big.

Thanks

[xnview]

Hi, All,

I use nconvert to convert tif files to ppm. The size of my tif files are about
25M each. When i convert it to ppm, It becomes 75M each. The command
i use is:

nconvert -in tiff -ctype grey -colors 256 -out ppm -truecolors 1.tif

I wander is there any way to preserve the size of the tif file. I want 25M
ppm, not 75M. It is too big.

PPM is uncompressed format, so it's not possible

[Guest]

Hi, All,

I use nconvert to convert tif files to ppm. The size of my tif files are about
25M each. When i convert it to ppm, It becomes 75M each. The command
i use is:

nconvert -in tiff -ctype grey -colors 256 -out ppm -truecolors 1.tif

I wander is there any way to preserve the size of the tif file. I want 25M
ppm, not 75M. It is too big.

PPM is uncompressed format, so it's not possible

Yes, i see. But the thing is that my tif file is also not compressed. I checked the property of the tif file and the converted ppm in xnview. I saw that the tif uses 1 byte for each pixel, while ppm uses 3 bytes for each pixel. So my question is whether it is possible to have a ppm using 1 byte each pixel? or every ppm should use 3 bytes for each pixel?

Thank you

[xnview]

Hi, All,

I use nconvert to convert tif files to ppm. The size of my tif files are about
25M each. When i convert it to ppm, It becomes 75M each. The command
i use is:

nconvert -in tiff -ctype grey -colors 256 -out ppm -truecolors 1.tif

I wander is there any way to preserve the size of the tif file. I want 25M
ppm, not 75M. It is too big.

PPM is uncompressed format, so it's not possible

Yes, i see. But the thing is that my tif file is also not compressed. I checked the property of the tif file and the converted ppm in xnview. I saw that the tif uses 1 byte for each pixel, while ppm uses 3 bytes for each pixel. So my question is whether it is possible to have a ppm using 1 byte each pixel? or every ppm should use 3 bytes for each pixel?

Thank you

PPM is only in RGB mode