You can experiment with different images using any of the images
supplied in HIPR or by a URL. Some of those available in HIPR have the
prefixes given here and .gif as the file extension: grayscale (cam1,
che1, cln1, fru1, man8, str1, str2, str3, tol1, txt2, wal2, wom1, wom2,
urb1, xra1) and range (bae1, fac1, phn2, ren1, ren2, ufo1, ufo2, ufo3)
Enter image specifiers (into the edit box at the top of the screen)
either as a full HIPR image filename (eg. cam1.gif) or by a
full URL. Only gif files can be loaded. Because of JAVA security, the
URL should refer to a publically accessible place, such as your
Pushing the Load Image button or pushing "Return" on the keyboard
causes the specified image to be loaded. The input image is displayed
in the Input display area below the control buttons, along with the
The Laplacian of Gaussian kernel is calculated using the kernel size
and the theta value. The input image is then convolved with this kernel
to produce the output image.
Image arithmetic may produce images with values less than 0 or
greater than 255. These values are clipped to 0 and 255, but Scaling
and Offset values can be entered to allow you to rescale the images
yourself before the clipping takes place, according to Output =
Scaling*Input + Offset.
The output is displayed to the right of the input image.
Pressing the green start button causes the operator to run. Pressing
the Stop button causes the operator to stop running. This is useful
if the system being run on is very slow and the operator is taking a
long time to complete.
The time box shows the amount of time which the
operator took to complete the process on the input image.
Image value inspection
You can inspect the input and result image pixel values by
depressing the left mouse button and moving the cursor over the desired
pixel. The pixel coordinates and gray-level value are displayed
underneath the image. Note that some images are larger than the
displayed 256x256 display window. Larger images are subsampled in an
You can find out about known problems with the system here.