Now that you have generated four images, you can play with them. In order to avoid getting involved with graphics devices at this stage, only commands which will run on any terminal will be used. The first thing to do is to examine their pixel values. There are several ways of doing this with KAPPA; one way is to use the LOOK command:
ICL> look INPIC - Image to be inspected/@ramp4/ >
The suggested value for the name of the image to be looked at is
@' character means `an object with the name of', thus
@ramp4' means `an object with the name of ramp4'.
In this case the system assumes that any character string you type is the name
of a data object; therefore you do not need to precede the name with an
In the example, the system realizes that the value of INPIC should be the name
of an image and it remembers that the name of the last image referred to was
However, look at `ramp1' first:
INPIC - Image to be inspected/@ramp4/ > ramp1
LOOK now accesses `ramp1' and displays the following information:
Title = KAPPA - Creframe Array is 10 by 10 pixels
The title of the image -- `
KAPPA - Creframe' -- was generated by the
CREFRAME program, and the array size is 1010 as expected.
This is followed by the next prompt:
CHOICE - Peep, Examine or List /'Peep'/ >
These are just different ways of listing the pixel values. The suggested value is `Peep', so try that by typing CR. You can also accept the suggested values for the next two prompts which specify the central point of the part of the image you are going to peep at:
XCEN - x centre pixel index of 7x7 box /5/ > YCEN - y centre pixel index of 7x7 box /5/ >
The `Peep' option will display the pixel values within a 77 box centred on pixel (XCEN, YCEN). Notice that the program has chosen the centre of the image as the suggested box centre. All the required parameter values have now been entered, so the program proceeds to display the specified box:
2 3 4 5 6 7 8 8 2 3 4 5 6 7 8 7 2 3 4 5 6 7 8 6 2 3 4 5 6 7 8 5 2 3 4 5 6 7 8 4 2 3 4 5 6 7 8 3 2 3 4 5 6 7 8 2 2 3 4 5 6 7 8 ANOTHER - Another inspection ? /YES/ >
Pixel indices are numbered from bottom left. In this case the pixel values are equal to their column number. Unlike CREFRAME, you are not returned to ICL but are given a chance to peep at another part of the image -- these decisions are made by the programmer. As the image you are peeping at is highly predictable, do not bother to examine it further but escape from the program by entering:
ANOTHER - Another inspection ? /YES/ > n ICL >
When a program asks for a `YES' or `NO' value, you can get away with `Y', `True', and `T' for `YES'; and `N', `False', and `F' for `NO'; regardless of case.
You can use the LOOK command to examine the pixel values of the other images you have created in a similar way to that shown above. The `List' option gives you the opportunity to store the output in a file:
ICL> look INPIC - Image to be inspected/@ramp1/ > Title = KAPPA - Creframe Array is 10 by 10 pixels CHOICE - Peep, Examine or List /'PEEP'/ > L XLOW - x start pixel index of sub-array /1/ > YLOW - y start pixel index of sub-array /1/ > XSIZE - x size of sub-array /10/ > YSIZE - y size of sub-array /10/ > FILENAME - Name of listing file /@LOOKOUT.LIS/ > Listing to LOOKOUT.LIS ANOTHER - Another inspection ? /YES/ > n ICL>
Notice in this case that the parameter prompts after that for `CHOICE' differ from those encountered before. This is because you have chosen the `List' option instead of the `Peep' option, and the program needs different information before it can proceed. Accept the suggested values for all the parameters until you come to `ANOTHER' again. This makes things quick and easy for you. The program writes the pixel listing to the file LOOKOUT.LIS which is written in your default directory. You should, therefore, be able to display it on the screen using the DCL `TYPE' command.
ICL> $ type lookout
will cause the contents of file LOOKOUT.LIS to be displayed on your terminal (in a folded form -- not shown here).
ADAM The Starlink Software Environment