Hi,
I have two binary files containing image data, and I want to go through them pixel by
pixel and read the image data into arrays and compare the pixel values (images have the
exact same dimensions but one is unsigned 1 byte per pixel, and the other signed 2 bytes
per pixel).

I am trying to read the data in using the following loop:

	for(int i = 0; i < num_blocks; i++) {
		auto resampbytes = resampFile.byChunk( resamp_buffer_size );
		auto normbytes = normalFile.byChunk( normal_buffer_size );
		ubyte[] resamp = cast(ubyte[]) resampbytes;
		short[] normaldata = cast(short[]) normbytes;

                //Process the data ...
	}

However, when I attempt to compile this I get the following errors:

Error: cannot cast from ByChunk to ubyte[]
Error: cannot cast from ByChunk to short[]

Oddly, the example for ByChunk in the documentation seems to do exactly what I think I am trying here, but apparently I am missing something.

Any help would be appreciated (also if there is a better way of doing what I am trying to do any pointers on that would be appreciated too!)

Regards,

Craig

On 18/03/2011 14:35, Craig Dillabaugh wrote:
> Hi,
> I have two binary files containing image data, and I want to go through them pixel by
> pixel and read the image data into arrays and compare the pixel values (images have the
> exact same dimensions but one is unsigned 1 byte per pixel, and the other signed 2 bytes
> per pixel).
>
> I am trying to read the data in using the following loop:
>
> 	for(int i = 0; i<  num_blocks; i++) {
> 		auto resampbytes = resampFile.byChunk( resamp_buffer_size );
> 		auto normbytes = normalFile.byChunk( normal_buffer_size );
> 		ubyte[] resamp = cast(ubyte[]) resampbytes;
> 		short[] normaldata = cast(short[]) normbytes;
>
>                  //Process the data ...
> 	}
>
> However, when I attempt to compile this I get the following errors:
>
> Error: cannot cast from ByChunk to ubyte[]
> Error: cannot cast from ByChunk to short[]
>
> Oddly, the example for ByChunk in the documentation seems to do exactly what I think I
> am trying here, but apparently I am missing something.
>
> Any help would be appreciated (also if there is a better way of doing what I am trying
> to do any pointers on that would be appreciated too!)
>
> Regards,
>
> Craig
>

File.byChunk is designed to be used with a foreach loop, you could try:

ubyte[] resamp = new ubyte[resamp_buffer_size];
short[] normaldata = new short[normal_buffer_size];
for(int i = 0; i < num_blocks; i++)
{
    resampFile.rawRead(resamp);
    normaldata.rawRead(normaldata);

    //Process the data ...
}

-- 
Aku MoD.

== Quote from Zirneklis (avoi@dingspam.cc)'s article
> On 18/03/2011 14:35, Craig Dillabaugh wrote:
> > Hi,
> > I have two binary files containing image data, and I want to go
through them pixel by
> > pixel and read the image data into arrays and compare the pixel
values (images have the
> > exact same dimensions but one is unsigned 1 byte per pixel, and
the other signed 2 bytes
> > per pixel).
> >
> > I am trying to read the data in using the following loop:
> >
> > 	for(int i = 0; i<  num_blocks; i++) {
> > 		auto resampbytes = resampFile.byChunk
( resamp_buffer_size );
> > 		auto normbytes = normalFile.byChunk
( normal_buffer_size );
> > 		ubyte[] resamp = cast(ubyte[]) resampbytes;
> > 		short[] normaldata = cast(short[]) normbytes;
> >
> >                  //Process the data ...
> > 	}
> >
> > However, when I attempt to compile this I get the following
errors:
> >
> > Error: cannot cast from ByChunk to ubyte[]
> > Error: cannot cast from ByChunk to short[]
> >
> > Oddly, the example for ByChunk in the documentation seems to do
exactly what I think I
> > am trying here, but apparently I am missing something.
> >
> > Any help would be appreciated (also if there is a better way of
doing what I am trying
> > to do any pointers on that would be appreciated too!)
> >
> > Regards,
> >
> > Craig
> >
> File.byChunk is designed to be used with a foreach loop, you could
try:
> ubyte[] resamp = new ubyte[resamp_buffer_size];
> short[] normaldata = new short[normal_buffer_size];
> for(int i = 0; i < num_blocks; i++)
> {
>      resampFile.rawRead(resamp);
>      normaldata.rawRead(normaldata);
>      //Process the data ...
> }

Thanks, that did the trick!
Craig