Panchromatic (Black & White) Images

The photographs showcased on this web site were captured at the north rim of the Grand Canyon National Park. Arizona. They have been processed in Photoshop and transformed into panchromatic (black and white) scenes.  Unlike color imagery, the basic physical properties in black and white images are more limited. 

 

Tone is the lightness or darkness of objects represented in an image. This definition applies to black and white, color, and false color images. Contrast is the variation in brightness from the lightest to the darkest objects. A maximum contrast occurs between two objects when one is expressed as white while the other is black, or in the case of color images, when there is maximum variance in brightness between hues (colors). Texture is the apparent smoothness or roughness which is exhibited in the spatial objects in an image by a variance in the distribution of brightness values. Smooth objects (sand) have many brightness values that are similar or the same value whether dark or light; while coarse textured objects (different rock types) have more variable (contrast) brightness values. Spatial objects that are expressed with similar or like brightness values are generally of a homogeneous feature class (sand). Large variations in brightness values can denote different feature classes; or display a pattern within a course textured field of brightness values which may be of a similar class such as row crops, an orchard, or other objects created within a human settlement. Tone and texture are closely associated and based upon the distribution of brightness values in a scene. Shape defines the geometry of objects, while size represents length, area, or volume. Shadow reveals the position of the sun, and can be useful in determining symmetry or asymmetry, size, and shape. This can be particularly effective in identifying higher relief features such as cliff faces. Shadows also illuminate smaller surface features casting a linear or area dimension. Pattern suggests something is influencing the spatial distribution of surface features, although a lack of pattern can also be significant in that it may suggest an anomaly that is not a function of a normal condition or process. Inclined rocks often control the alignment of trees aligned in a linear pattern, and suggest the underlying structure of the rocks has some control or influence on the distribution of the surface feature (trees). Specific vegetation species that are not indigenous to an area may suggest something more interesting is a contributing factor. Density refers to the number of objects taking up an area or region which may be an indication of a physical process such as volcanism and lava flows overlying a surface of different rock types. Clustering of objects can generally indicate something is controlling the manner in which they have assembled.