Team Slytherin: Difference between revisions
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| Line 99: | Line 99: | ||
sumX = 0; | sumX = 0; | ||
sumY = 0; | sumY = 0; | ||
/* image boundaries */ | /* image boundaries */ | ||
if(Y==0 || Y==originalImage.rows-1) | if(Y==0 || Y==originalImage.rows-1) | ||
| Line 105: | Line 104: | ||
else if(X==0 || X==originalImage.cols-1) | else if(X==0 || X==originalImage.cols-1) | ||
SUM = 0; | SUM = 0; | ||
/* Convolution starts here */ | /* Convolution starts here */ | ||
else { | else { | ||
/*-------X GRADIENT APPROXIMATION------*/ | /*-------X GRADIENT APPROXIMATION------*/ | ||
for(I=-1; I<=1; I++) { | for(I=-1; I<=1; I++) { | ||
| Line 116: | Line 113: | ||
} | } | ||
} | } | ||
/*-------Y GRADIENT APPROXIMATION-------*/ | /*-------Y GRADIENT APPROXIMATION-------*/ | ||
for(I=-1; I<=1; I++) { | for(I=-1; I<=1; I++) { | ||
| Line 124: | Line 120: | ||
} | } | ||
} | } | ||
/*---GRADIENT MAGNITUDE APPROXIMATION (Myler p.218)----*/ | /*---GRADIENT MAGNITUDE APPROXIMATION (Myler p.218)----*/ | ||
SUM = abs(sumX) + abs(sumY); | SUM = abs(sumX) + abs(sumY); | ||
} | } | ||
if(SUM>255) SUM=255; | if(SUM>255) SUM=255; | ||
if(SUM<0) SUM=0; | if(SUM<0) SUM=0; | ||
*(edgeImage.data + X + Y*originalImage.cols) = 255 - (unsigned char)(SUM); | *(edgeImage.data + X + Y*originalImage.cols) = 255 - (unsigned char)(SUM); | ||
fwrite((edgeImage.data + X + Y*originalImage.cols),sizeof(char),1,bmpOutput); | fwrite((edgeImage.data + X + Y*originalImage.cols),sizeof(char),1,bmpOutput); | ||
} | } | ||
} | } | ||
Revision as of 05:19, 22 February 2012
Team Members
- Kevin Townsend
- Bhavani Satyanarayana Rao
- Chidvila Gaddam
Assignment1
Running the sample application with script files
- The runcp script located in the SampleAppVadd can be used to run the application in HW which sets the appropriate environment variables and runs the UserApp.exe export CNY_PDK_PROJ = ~/pdk_sample/cae_pers_vadd ./runcp
- The run script located in the SampleAppVadd can be used to run the application in SW
- The scripts above can be used to run the application on Simulator using the "-vsim" option which sets the environment variable CNY_CAE_EMULATOR to ./run_simulation ./runcp -vsim or ./run -vsim
| Environment Variables | Software | ModelSim | Hardware |
|---|---|---|---|
| CNY_SIM_THREAD | libcpSimLib2.so | libcpSimLib2.so | unset |
| CNY_CAE_EMULATOR | <location for CaeSimPers> | ./run_simulation | unset |
Changes made to run the application on ModelSim
- Setup as explained in here [[1]]
- Set the CNY_PDK_PROJ environment variable to the location of cae_pers_vadd export CNY_PDK_PROJ = ~/pdk_sample/cae_pers_vadd
- Copied Jones' my_makefile from the temp dir and replaced the makefile in CY_PDK_PROJ/testbench
- Add line to the makefile in testbench dir CNY_PDK_MODELSIM_USER_SIM_OPTIONS= -i -do "run -all"
- Modify the values of LIB_DIR and LDFLAGS from 32-bit to 64-bit as given below LIB_DIR = lib64 LDFLAGS = -m64
Error creating thumbnail: File missing
Extra Credit: Exploring gdb
- We invoked gdb using the gdb <programname> command or by using the run/runcp script files in with "-gdb" option gdb UserApp.exe or ./run -gdb Error creating thumbnail: File missing
- One can find different command classes on gdb by typing help.To get details on a particular command class/command, type help on gdb followed by the name of the command class/command Error creating thumbnail: File missing
- We explored some commands like run, start (to begin execution), stepi (for single instruction stepping into a file), kill (kill a running program) and quit on gdb Error creating thumbnail: File missing
Assignment2
About Sobel Algorithm
Sobel Algorithm is used for edge detection in image processing.The link[2] explains
- Why edge detection is important?
- How sobel algorithm uses the gradient method (jump in the pixel values along edges in the images compared to the pixels around it) to detect edges in images?
The Algorithm
- Use Sobel masks to find the gradient of a pixel w.r.t its 8 immediate neighboring pixel values. The Sobel masks are GX={(-1,0,+1),(-2,0,+2),(-1,0,+1)) which gives the gradient in the x direction and Gy={(+1,+2,+1),(0,0,0),(-1,-2,-1)} which gives the gradient in the x direction.
- Find the approximate magnitude of the gradient using the formula |G|=|Gx|+|Gy|
- Compare |G| against the threshold values (0 and 255 in our case). If (|G| > 255) then the pixel value is 0 in the output image. If (|G| < 0) then the pixel value is 255 in the output image.
- Repeat the above steps for all the pixels in the image
C code for Sobel Algorithm
Source: Edge Detection Tutorial-Author: Bill Green (2002)[3]
/*---------------------------------------------------
SOBEL ALGORITHM STARTS HERE
---------------------------------------------------*/
for(Y=0; Y<=(originalImage.rows-1); Y++) {
for(X=0; X<=(originalImage.cols-1); X++) { sumX = 0; sumY = 0;
/* image boundaries */
if(Y==0 || Y==originalImage.rows-1) SUM = 0; else if(X==0 || X==originalImage.cols-1) SUM = 0; /* Convolution starts here */ else { /*-------X GRADIENT APPROXIMATION------*/ for(I=-1; I<=1; I++) { for(J=-1; J<=1; J++) { sumX = sumX + (int)( (*(originalImage.data + X + I +
(Y + J)*originalImage.cols)) * GX[I+1][J+1]);
} } /*-------Y GRADIENT APPROXIMATION-------*/ for(I=-1; I<=1; I++) { for(J=-1; J<=1; J++) { sumY = sumY + (int)( (*(originalImage.data + X + I +
(Y + J)*originalImage.cols)) * GY[I+1][J+1]);
} } /*---GRADIENT MAGNITUDE APPROXIMATION (Myler p.218)----*/
SUM = abs(sumX) + abs(sumY);
}
if(SUM>255) SUM=255;
if(SUM<0) SUM=0;
*(edgeImage.data + X + Y*originalImage.cols) = 255 - (unsigned char)(SUM); fwrite((edgeImage.data + X + Y*originalImage.cols),sizeof(char),1,bmpOutput); }
}