Balach Masud

When we look at a blurred image, we see that the colors from various objects are spread out in the image over an area around the objects.  Mathematically, this is exactly what is happening.  Instead of the light from one point in the scene corresponding with the light at one point in the image, the light from each point in the scene is spread out over multiple points in the image.   The function that describes this spread is called the point spread function (PSF).  The PSF is also the impulse response of the imaging system, and in applications dealing with blur, is sometimes referred to as the “blur kernel”.

IMAGE COMPRESSION Many different image compression schemes exist, and several, often completely, different methods can be used for each of the different steps in an image compression scheme, and the different methods can often be combined in any way. Some examples are the Matlab implementation of SPIHT which is used as a reference compression scheme here. Also Matlab commands imwrite and imread supports several image formats, many of them include effective compression. The latest versions (from R2010b) also support the effective JPEG-2000 format (JP2 option). The standard JPEG format is also supported but the compression rate is not as good as expected, perhaps the overhead information is relatively large. This page contains several Matlab functions, m-files, a brief explanation and some examples for image compression. The included functions can be used for some of the many steps or stages often done in image compression. It is not a complete finished codec, like JPEG or JPEG-2000. ...