ce150_readme.txt

说明：该代码是一个使用DSP库函数变量进行JPEG编码的简单应用范例。开发环境：用MPLAB C30编译

						Readme File for Code Example:
              					CE150 - JPEG Entropy Coding
				          ----------------------------------------

This file contains the following sections:
1. Code Example Description
2. Folder Contents
3. Suggested Development Resources
4. Reconfiguring the project for a different dsPIC33F device
5. Revision History


1. Code Example Description:
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This example shows a simple JPEG encoder using the functions available in the DSP library. 

The main blocks are as follows:
1.Zero Center Transformation: int VectorLevelShiftIP(fractional*, int, int);
Centers the input 8x8 matrix around 0 by performing level shifting by 128.

2.2-D Type II DCT: int DCT_2D(fractional*, int, int, fractional*, fractcomplex*, fractcomplex*, int, int);
Performs 2D DCT on the zero centered matrix using 1D type II DCT function in DSP library. It is also supported by vector and matrix functions.

3.Perceptual Quantization: int VectorDivideIP(fractional*, fractional*, int);
Performs quantization using the regular JPEG quantization matrix.

4.Zig-zag Transformation: int Matrix2Vector_ZigZag(fractional*, fractional*, int, int);
Arranges the 2-D Type II DCT transformed, quantized data in to a vector in a JPEG zig-zag fashion.

5.Huffman Encoder: int EntropyEncoder(fractional*, fractional*, int);
Encodes the zig-zag arranged vector using Huffman entropy coding. 

The example takes an 8x8 image data block as input. Prints the transformed data at every stage and finally the code bits and the achieved compression rate. 


2. Folder Contents:
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This folder contains the following sub-folders:
a. C:\Program Files\Microchip\MPLAB C30\support\gld
        This folder will have the device GLD file, it is used for building the project. 
	This file was provided with the MPLAB