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To accomplish this, we will need to take advantage of the IDM by initializing the input and output streams. At the start ofthe function, two instantiations of a new structure dstr_t are declared. You can view the structure contents of dstr_t on p. 2-11 of the IDK Programmer's Guide . The structure contents are defined with calls to dstr_open() . This data flow for the pre-scale is shown in data flow .

Data flow of input and output streams.

To give you a better understanding of how these streams are created, let's analyze the parameters passed in the first callto dstr_open() :

External address: in_image->data

This is a pointer to the place in memory serving as the source of our input data (it's the source because the lastfunction parameter is set to DSTR_INPUT ).

External size: (rows + num_lines) * cols = (240 + 2) * 640

This is the total size of our input data. We will only be taking every other line from in_image->data , so only 240 rows. The extra two rows are for buffer.

Internal address: int_mem

This is a pointer to an 8x640 lexographic array, specifically scratchpad->int_data . This is where we will be putting the data on each call to dstr_get() .

Internal size: 2 * num_lines * cols = 2 * 2 * 640

The size of space available for data to be input into int_mem from in_image->data . Because double buffering is used, num_lines is set to 2.

Number of bytes/line: cols = 640, number of lines: num_lines = 2

Each time dstr_get() is called, it will return a pointer to 2 lines of data, 640 bytes inlength.

External memory increment/line: stride*cols = 1*640

Left as an exercise.

Window size: 1 for double buffered

The need for the window size is not really apparent here. It will become apparent when we do the 3x3 blockconvolution. Then, the window size will be set to 3. This tells the IDM to send a pointer to 3 lines of data when dstr_get() is called, but only increment the stream's internal pointer by 1 (instead of 3) the next time dstr_get() is called. This is not a parameter when setting up an output stream.

Direction of input: dstr_input

Sets the direction of data flow. If it had been set to DSTR_OUTPUT (as done in the next call to dstr_open() ), we would be setting the data to flow from the Internal Address to the External Address.

Once our data streams are setup, we can begin processing by calling the component function pre_scale() (in pre_scale.c ) to operate on one block of data at a time. This function will perform the horizontal scaling byaveraging every two pixels. This algorithm operates on four pixels at a time. The entire function is iterated within pre_scale_image() 120 times, which is the number of rows in each quadrant. Before pre_scale_image() exits, the data streams are closed, and one line is added to the top and bottom of theimage to provide context necessary for the next processing steps. Now that the input image has been scaled to a quarterof its initial size, we will proceed with the four image processing algorithms. In img_proc.c , the set_ptr() function is called to set the variable out_ptr to point to the correct quadrant on the 640x480 output image. Then copy_image() , copy_image.c , is called, performing a direct copy of the scaled input image into the lower right quadrant of theoutput.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Ece 320 - spring 2003. OpenStax CNX. Jan 22, 2004 Download for free at http://cnx.org/content/col10096/1.2
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