Author/Editor		Sandstroem, Matz; Lindqvist, Jan Erik
Title		An alternative method for treatment of edge effects
Type		članek
Source		Image Anal Stereol
Vol. and No.		Letnik 20, št. Suppl 1
Publication year		2001
Volume		str. 100-5
Language		eng
Abstract		This contribution presents an alternative approach, the SP method, which reduces the need for edge object corrections when the 3D size distribution is calculated based on measurement of the maximum Feret diameter (Fm). The edges of the image frame greatly affect parameters like area aud intercept length, and must therefore be taken into account when the size distribution is calculated based on these parameters. Large objects will often be incorrectly measured because of the high probability of intersecting the frame. Increasing the field size gives low resolution and problems with the smallest objects. Traditional methods for correcting for edge effects, such as guarded frame or correction of the number of objects, are not suitable for measuring the size distribution of objects with large variations in size. If the geometrical size distribution is calculated based on measurement of maximum Feret diameter (Fm) the need for correction decreases. The reason is that more than half of a spherical object must be outside the frame before the Feret diameter is wrongly measured. Furthermore, the measured Feret diameter must be smaller than the lower class limit before the object will be wrongly classitied. The larger the object is, the larger must the class be to avoid errors in classification. Geometrical classification should therefore be used. Large objects will be classifled in broad classes, which minimizes the error, and small objects will be classified in narrow classes.
Descriptors		PARTICLE SIZE IMAGE PROCESSING, COMPUTER-ASSISTED