I have been working on image processing. But there is one thing that has made me confused. What is difference between structured image and textured image. In my idea, both are the same. But recently, I read a paper that claimed that they are different. Somebody let me know what diffrerences they have?
Imho there is no "mathematical" description of either terms.
Both (texture and stucture) can be viewed as a repeating pattern. In the case of texture, the pattern might get a more random perturbation (think at an image of sand or grass).
In the case of a structured image you might get less random and more systematical perturbation (Think of a roof picture with tiles) Sometimes more info can be extracted from structured images. Imagine that you can actually get some 3D info by examining the way the pattern varies along one direction or another.
Of course I could be completely wrong and the "structure image" has a concrete definition for the author that you quote.
I found two examples where 3D info is extracted from textural information. Chapter 9.5 "Shape from Texture" from "Introductory Techniques for 3-D Computer Vision" by Emanuele Trucco, Alessandro Verri (1998 ed) and Chapter 12.4 3D Cues Available in 2D Images from "Computer Vision" by L. Shapiro and G. Stockman (2000 ed)
There, you have the idea of deterministic texture vs stochastic texture. Also read Jedi Commymullah answer for some other insights.
Images are free:
Texture is an oscillatory component capturing details and noise. The structured part could be a geometric and smoothly varying component.
I agree with visoft's answer, but my understanding of the term "structured image' varies. If visoft's pictures describe the answer to your question, then it is the importance of shadow (its angle, length, darkness) in the interpretation of an image that distinguishes the two. In a 3D world, structured images change with the camera position. With texture images this is not the criterion.
Though first to my mind, structured image, means an image that is composed of arranged objects, representing the polarity of textured image, indeed.
Finally, "structured image" can be the term for an image that is composed of individual graphic elements. From here: A structured image is a hierarchical description of a single output image raster; objects contributing to the output raster may originate from text, graphics, other rasters or a combination thereof, and all maintain their heritage for selectability and modification. In this sort of structured image, each input may be considered an object.
Traditionally, elements of a "textured image" may be drawn simultaneously, automatically, or artistically, but a record of how a textured image is generated is unnecessary other than the configurations of any automatic process involved. The artists relies solely upon Undo/Redo to salvage their efforts.
Software can make the difference between the two a matter of taste, in my opinion.