retrieve blob field's textual data from tables in Sybase

I am interacting with a Sybase database, which is being used at a customers site for running PowerSchool. I don’t think the OS of the target system is involved with this issue.
I cannot determine how to retrieve blob fields’ textual data from certain tables in Sybase. The actual field datatype in question is “IMAGE” which is merely being used to store (potentially) large amounts of textual data.

For example, here is a table definition I am encountering (written in SQL):
Query:
sp_columns sectionscores
Edited Response:

column_name                    data_type   type_name        precision   length      

-----------                    ----------- ---------        ----------- -----------

DCID                                    4 int                       10           4

ID                                        4 int                       10           4

SectionID                              4 int                       10           4

STID                                     4 int                       10           4

Assignment                          -4 image             2147483647          16

Percent                                 -4 image             2147483647          16

Score                                   -4 image             2147483647          16

GRD                                     -4 image             2147483647          16

comment_value                           -4 image             2147483647          16

Unused1                                  4 int                       10           4
Previous Query Attempts:

I have already tried SQL of the following form (this query is for testing purposes) and other variations of this:

DECLARE @textptr binary(16), @blobsize int, @chunkindex int, @chunksize int
SET TEXTSIZE 64

BEGIN TRAN
SELECT @textptr=TEXTPTR(Assignment), @blobsize=DATALENGTH(Assignment),

      @chunkindex=0, @chunksize=CASE WHEN @@TEXTSIZE < @blobsize THEN

      @@TEXTSIZE ELSE @blobsize END

FROM sectionscores WHERE DCID=318612


IF(@textptr IS NOT NULL) AND (@chunksize > 0)

WHILE (@chunkindex < @blobsize) AND (@@ERROR = 0) BEGIN

      READTEXT sectionscores.Assignment @textptr @chunkindex @chunksize

      SELECT @chunkindex=@chunkindex+@chunksize,

            @chunksize=CASE WHEN (@chunkindex+@chunksize) > @blobsize THEN @blobsize-@chunkindex ELSE @chunksize END

END

COMMIT TRAN

SET TEXTSIZE 0

All I get back from the usage of READTEXT is merely the same Data Pointer value as if I had just issued the following query:

SELECT Assignment FROM sectionscores WHERE DCID=318612

THanks