基礎圖像處理---圖像讀寫/保存與基礎圖像繪製框架(純C代碼，不依賴任何第三方庫)

對於初學者要入門圖像處理這一行，想必大家都遇到這樣的問題：

1，單純用C/C++語言進行圖像處理，苦於各種圖像讀寫保存的庫的加載調用，或者說實在不想用MFC，不想用CImage等，但是又沒有辦法；

2，想用高級語言，比如C#/JAVA等，因爲他們有強大的圖像加載保存API，可以直接方便的調用，但是，算法處理還是C/C++爲主，畢竟用C#/JAVA做圖像處理項目的太少太少；

3，如果想要自己實現圖像的讀寫/保存算法，沒有一定的功底，幾乎不太可能，嚴重阻礙了初學者學習的熱情；

對於一個初學者，或者小白來說，要搞清楚這些東西，簡直如同噩夢，針對這些問題，本文給出C語言實現的一個更適合初學者入門的基礎圖像處理框架：

①，BMP/JPG/PNG/TGA格式圖像讀寫/保存代碼；

②，點/線/圓/三角形/長方形/多邊形等常用形狀的繪製代碼；

上述兩點，均由C語言實現，不依賴任何第三方庫，極大的方便了大家學習使用；

1，BMP/JPG/PNG/TGA格式圖像讀寫

這部分代碼來自於github上的開源代碼：https://github.com/XiuSdk/stb

stb代碼框架中包含了各種圖像讀寫操作，所有代碼基於C語言實現，不依賴任何第三方，這裏，我進行了簡單的封裝，接口如下：

/************************************************************
*Function:  f_SF_ImgBase_ImageLoad
*Description: Image loading
*Params:    fileName-image file path,eg:"C:\\test.jpg".
*           width-image width.
*           height-image height.
*           component-the bits per pixel.
*                     1           grey
*                     2           grey, alpha
*                     3           red, green, blue
*                     4           red, green, blue, alpha
*Return:    image data.
************************************************************/
	unsigned char* f_SF_ImgBase_ImageLoad(char* fileName, int* width, int* height, int* component);
/************************************************************
*Function:  f_SF_ImgBase_ImageSave
*Description: Image loading
*Params:    fileName-image file path,eg:"C:\\save.jpg".
*           width-image width.
*           height-image height.
*           data-the result image data to save, with format BGRA32.
*           format-image format,0-BMP,1-JPG,2-PNG,3-TGA
*Return:    0-OK.
************************************************************/
	int f_SF_ImgBase_ImageSave(char const *fileName, int width, int height, const void* data, int format);

簡單的兩個接口，調用也非常簡單，這兩個接口，圖像buffer都是bgra32格式，調用如下：

char* srcPath = "Test\\test.jpg";
	char* savePath = "Result\\res.jpg";
	int width = 0, height = 0, stride = 0, component = 0, mWidth = 0, mHeight = 0, mStride = 0, mComponent = 0;
	unsigned char* srcData = f_SF_ImgBase_ImageLoad(srcPath, &width, &height, &component);
	stride = width * 4;
    //srcData爲bgra32數據
	f_SF_ImgBase_ImageSave(savePath, width, height, srcData, 1);

有了這兩個接口，初學者再也不用接入什麼MFC/CImage/LIBJPG/LIBPNG等複雜的東西了！

2，圖像基礎繪製

有了圖像讀寫，我們在實際應用中，往往需要在圖像中繪製一些標籤，比如人臉檢測的人臉框，繪製一個三角形，矩形，圓形，或者更復雜的繪製任意一個多邊形等等，這些東西，以往我們都是使用opencv或者使用上層語言的GDI+繪製來實現的，但是，這裏，本人用C語言實現了這些功能，一共350行代碼，包含如下功能：

①繪製實心點和空心點

②繪製線段，允許設置線的寬度

③繪製三角形/矩形/多邊形/圓形/橢圓，允許設置畫筆寬度

④填充三角形/矩形/多邊形/圓形/橢圓

功能接口以輸入bgra32格式爲主，接口如下：

/********************************************************************
*Function: ImgDrawPoints
*Description: Draw points using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          points-points array,eg:[x0,y0,x1,y1...].
*          pointNum-number of points.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          radius-size of point.
********************************************************************/
void ImgDrawPoints(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int points[], int pointNum, int r, int g, int b, int radius);

/********************************************************************
*Function: ImgDrawHollowPoints
*Description: Draw hollow points using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          points-points array,eg:[x0,y0,x1,y1...].
*          pointNum-number of points.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of pen color.
*          radius-size of point.
********************************************************************/
void ImgDrawHollowPoints(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int points[], int pointNum, int r, int g, int b, int penSize, int radius);
/********************************************************************
*Function: ImgDrawLine
*Description: Draw line using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          x1-x position of start point.
*          y1-y position of start point.
*          x2-x position of end point.
*          y2-y position of end point.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of line.
********************************************************************/
void ImgDrawLine(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride,int x1, int y1, int x2, int y2, int r, int g, int b, int penSize);
//draw rectangle
/********************************************************************
*Function: ImgDrawRectangle
*Description: Draw rectangles using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          x-x position of start point.
*          y-y position of start point.
*          w-width of rectangle.
*          h-height of rectangle.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of lines.
********************************************************************/
void ImgDrawRectangle(unsigned char*srcData, int srcWidth, int srcHeight, int srcStride, int x, int y, int w, int h, int r, int g, int b, int penSize);
/********************************************************************
*Function: ImgDrawTriangle
*Description: Draw triangles using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          x-x position of frist point.
*          y-y position of frist point.
*          x1-x position of second point.
*          y1-y position of second point.
*          x2-x position of third point.
*          y2-y position of third point.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of lines.
********************************************************************/
void ImgDrawTriangle(unsigned char*srcData, int srcWidth, int srcHeight, int srcStride, int x, int y, int x1, int y1, int x2, int y2, int r, int g, int b, int penSize);

/********************************************************************
*Function: ImgDrawCircle
*Description: Draw circle using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          centerX-x position of center point.
*          centerY-y position of center point.
*          radius-radius of circle.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of pen color.
********************************************************************/
void ImgDrawCircle(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int centerX, int centerY, int radius, int r, int g, int b, int penSize);
/********************************************************************
*Function: ImgDrawFillCircle
*Description: Fill circle using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          centerX-x position of center point.
*          centerY-y position of center point.
*          radius-radius of circle.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawFillCircle(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int centerX, int centerY, int radius, int r, int g, int b);
/********************************************************************
*Function: ImgDrawFillTriangle
*Description: Fill triangles using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          x-x position of frist point.
*          y-y position of frist point.
*          w-width of rectangle.
*          h-height of rectangle.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawFillRectangle(unsigned char*srcData, int srcWidth, int srcHeight, int srcStride, int x, int y, int w, int h, int r, int g, int b);
/********************************************************************
*Function: ImgDrawFillTriangle
*Description: Fill triangles using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          x-x position of frist point.
*          y-y position of frist point.
*          x1-x position of second point.
*          y1-y position of second point.
*          x2-x position of third point.
*          y2-y position of third point.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawFillTriangle(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int x, int y, int x1, int y1, int x2, int y2, int r, int g, int b);
/********************************************************************
*Function: ImgDrawPolygon
*Description: Draw Polygon using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          polygonPoints-points array of polygon, eg:[x0, y0, x1, y1,...].
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
*          penSize-size of pen color.
********************************************************************/
void ImgDrawPolygon(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int polygonPoints[], int pointNum, int r, int g, int b, int penSize);
/********************************************************************
*Function: ImgDrawFillPolygon
*Description: Fill Polygon using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          polygonPoints-points array of polygon, eg:[x0, y0, x1, y1,...].
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawFillPolygon(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int polygonPoints[], int pointNum, int r, int g, int b);
/********************************************************************
*Function: ImgDrawEllipse
*Description: Draw Ellipse using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          centerX-center x of eclipse.
*          centerY-center y of eclipse.
*          A-A of eclipse(A > B).
*          B-B of eclipse(B < A).
*          penSize-size of pen color.
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawEllipse(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int centerX, int centerY,  int A, int B, int r, int g, int b, int penSize);
/********************************************************************
*Function: ImgDrawFillEclipse
*Description: Fill Ellipse using specified color.
*Params:  
*          srcData-source image with bgra32 pixelformat.
*          srcWidth-width of source image.
*          srcHeight-height of source image.
*          srcStride-stride of source image.
*          centerX-center x of eclipse.
*          centerY-center y of eclipse.
*          A-A of eclipse(A > B).
*          B-B of eclipse(B < A).
*          r-Red component of pen color.
*          g-Green component of pen color.
*          b-Blue component of pen color.
********************************************************************/
void ImgDrawFillEllipse(unsigned char* srcData, int srcWidth, int srcHeight, int srcStride, int centerX, int centerY, int A, int B, int r, int g, int b);

調用舉例如下：

	//Drawing Rectangle
	int x = 100, y = 100, w = 50, h = 50;
	ImgDrawRectangle(srcData, width, height, stride, x, y, w, h, penColorR, penColorG, penColorB, 3);
	//Drawing Triangle
	ImgDrawTriangle(srcData, width, height, stride, x, y, x + 100, y, x, y + 100, penColorG, penColorR, penColorB, 1);
	//fill rectangle
	ImgDrawFillRectangle(srcData, width, height, stride, 100, 300, w, h, penColorR, penColorG, penColorB);
	//fill triangle
	ImgDrawFillTriangle(srcData, width, height, stride, x, y + 100, x + 100, y + 100, x, y + 200, penColorG, penColorR, penColorB);
	int polyPoints[8] = {200, 200, 250, 130, 280, 220, 230, 300};
	//draw polygon
	ImgDrawPolygon(srcData, width, height, stride, polyPoints, 4, 200, 100, 50, 2);
	int polyPoints1[8] = {300, 400, 350, 130, 480, 220, 330, 400};
	//fill polygon
	ImgDrawFillPolygon(srcData, width, height, stride, polyPoints1, 4, 200, 100, 250);
	//fill ellipse
	ImgDrawFillEllipse(srcData, width, height, stride, 500, 500, 100, 50, 155, 245,67);
	//draw ellipse
	ImgDrawEllipse(srcData, width, height, stride, 200, 500, 100, 50, 255, 45,67, 1);

對應效果圖如下：

整體算法編譯DLL不足100K，可謂輕量級的庫。

在使用時，只需要把庫ImageProcessBasicFramework.dll和ImageProcessBasicFramework.lib以及頭文件ImgBasic文件夾放到工程路徑下，點擊工程屬性，配置link-input與VC++目錄即可，如下所示：

最後，給出代碼庫及DEMO下載鏈接：https://download.csdn.net/download/trent1985/11218979

代碼庫爲VS2010 編譯，DEMO爲VS2010工程。