Description
Project 1: Given a grey-scale image, you are to perform the following tasks:
1. Compute histogram of the input image and display the histogram in two formats, see the output description below.
2. Perform binary threshold operation on the input image with a given threshold value via argv[].
3. Output the result of the threshold in two formats, see the output description below.
************************************** Language: C++
**************************************
*** Name your soft copy and hard copy files using the naming convention as given in the project submission requirement discussed in a lecture and is posted in Google Classroom.
*** All on-line submission MUST include Soft copy (*.zip) and hard copy (*.pdf) in the same email attachments with correct email subject as stated in the email requirement; otherwise, your submission will be rejected.
1. Run your program on data1 with threshold 5
2. Run your program on data2 with threshold 38.
3. Include in your hard copy *.pdf file as follows: – Cover page.
– source code.
– Output outFile1 for data 1.
– Output outFile2 for data 1.
– Output outFile3 for data 1.
– Output outFile4 for data 1.
– Output outFile1 for data 2.
– Output outFile2 for data 2.
– Output outFile3 for data 2.
– Output outFile4 for data 2.
********************************************** I. Input: There are two inputs to the program. ********************************************** a) inFile1 (argv[1]):
a txt file representing a grey-scale image, where the first text line (4 integers) is the “header” of the input image then follows by rows and cols of integers.
For example,
4 6 1 12 // image has 4 rows,6 cols, min is 1, max is 12
2 3 4 11 2 9
5 6 11 2 10 7
1 1 12 1 9 9
4 5 6 9 9 9
b) a threshold value (argv[2])
******************************************* II. Outputs: There are four output files. *******************************************
a) OutFile1 (use argv[3]): For the output of histogram in the following format (to be used in the future project):
The first text-line is the image header, follows by a list of pairs <i, j> where i = 0 to max and j is the hist(i) For example:
4 6 1 12
0 0
1 3
2 3
3 1
4 2
5 2
6 2
7 1
8 0
9 6
10 1
11 2
12 1
b) OutFile2 (use argv[4]): Display the histogram (for visual) as follows:
first text line is the image header then follows by a list of : greyScale (numpixels): number of +’s for example, the output of the histogram of the above image would be: Use the maximum of 70 +’s for all counts greater than 70. Use small font size so that 70 +’s can be printed on one text line.
4 6 1 12
0 (0):
1 (3):+++
2 (3):+++
3 (1):+
4 (2):++
5 (2):++
6 (2):++ 7 (1):+ 8 (0):
9 (6):++++++
10 (1):+
11 (2):++
12 (1):+
c) outFile3 (use argv[5]): The result of the threshold of the input image. (To be used for future processing.)
Note: The output binary image also needs to have the image header. For example, given the above image and 6 as the threshold value then the binary image would be:
4 6 0 1 // notice the min and max values have changed 0 and 1.
0 0 0 1 0 1
0 1 1 0 1 1
0 0 1 0 1 1
0 0 1 1 1 1
d) outFile4 (use argv[6]): (For nice visual purposes).
For example, given the above threshold image, the pretty print replace 0 with a period.
4 6 0 1
. . . 1 . 1
. 1 1 . 1 1
. . 1 . 1 1
. . 1 1 1 1
******************************* III. Data structure:
*******************************
– image class
– numRows (int)
– numCols (int)
– minVal (int)
– maxVal (int)
– histAry(int*) //a 1D integer array, size of maxVal + 1
// need to be dynamically allocated at run time
– thresholdValue (int) // via argv[2]
Methods:
– computeHist(…) // The algorithm is given in the lecture note
– printHist (…)// on your own; see the above example
– dispHist (…)// on your own; see the above example
– threshold(…) // The algorithm is given below
*******************************
IV. main (…)
*******************************
step 0: inFile ß open input file use argv[1] open all 4 outFiles via argv[3], argv[4], argv[5], argv[6]
step 1: numRows, numCols, minVal, maxVal ß read from inFile step 2: histAry ß dynamically allocate and initialize to 0 step 3: ComputeHist (…) step 4: printHist(outFile1) Step 5: dispHist (outFile2) step 6: close inFile
reopen inFile
Step 7: thrVal ß get from argv[2]
outFile3 ß “The threshold value uses is ” thrVal outFile4 ß “The threshold value uses is ” thrVal
Step 8: threshold (inFile, outFile3, outFile4, thrVal)
step 9: close all files
*************************************************
V. threshold (inFile, outFile3, outFile4, thrVal) ************************************************* Step 0: minVal ß 0 maxVal ß 1
Step 1: outFile3, outFile4 ß output numRows, numCols, minVal and maxVal
Step 2: pixelValß read from inFile one integer at a time
Step 3: if pixelVal >= thrVal
outFile3 <– write 1 follows by a blank outFile4 <– write 1 follows by a blank
else
outFile3 <– write 0 follows by a blank outFile4 <– write . follows by a blank
Step 4: repeat step 2 to 3 until the inFile is empty
