diff --git a/input/hello.bmp b/input/hello.bmp
new file mode 100644
index 0000000..ea7d688
Binary files /dev/null and b/input/hello.bmp differ
diff --git a/input/test1.bmp b/input/test1.bmp
new file mode 100644
index 0000000..5307b86
Binary files /dev/null and b/input/test1.bmp differ
diff --git a/output/output.bmp b/output/output.bmp
new file mode 100644
index 0000000..dc93635
Binary files /dev/null and b/output/output.bmp differ
diff --git a/zoom.cpp b/zoom.cpp
new file mode 100644
index 0000000..9950cbe
--- /dev/null
+++ b/zoom.cpp
@@ -0,0 +1,98 @@
+#include <Windows.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+ 
+int main(int argc, char ** argv)
+{
+	FILE *fp = fopen("C:\\Users\\leong\\Desktop\\bmp_exam\\input\\hello.bmp","rb");
+	if (fp == 0)
+		return 0;
+	BITMAPFILEHEADER fileHead;
+	fread(&fileHead, sizeof(BITMAPFILEHEADER), 1, fp);
+	BITMAPINFOHEADER infoHead;
+	fread(&infoHead, sizeof(BITMAPINFOHEADER), 1, fp);
+	int width = infoHead.biWidth;
+	int height = infoHead.biHeight;
+	int biCount = infoHead.biBitCount;
+ 
+	RGBQUAD *pColorTable;
+	int pColorTableSize = 0;
+ 
+	pColorTable = new RGBQUAD[256];
+	fread(pColorTable, sizeof(RGBQUAD), 256, fp);
+	pColorTableSize = 1024;
+ 
+	unsigned char *pBmpBuf;
+	int lineByte = (width*biCount / 8 + 3) / 4 * 4;
+	pBmpBuf = new unsigned char[lineByte*height];
+	fread(pBmpBuf, lineByte*height, 1, fp);
+	fclose(fp);
+ 
+	printf("倍：");
+	// float lx, ly;
+	// scanf("%f%f", &lx, &ly);
+	// int dstWidth = round(double(lx*width));
+	// int dstHeight = round(double(ly*height));
+	float k;
+	scanf("%f", &k);
+	int dstWidth = round(double(k*width));
+	int dstHeight = round(double(k*height));
+	int lineByte2 = (dstWidth*biCount / 8 + 3) / 4 * 4;
+	
+	unsigned char*pBmpBuf2;
+	pBmpBuf2 = new unsigned char[lineByte2*dstHeight];
+	for (int i = 0; i < dstHeight; ++i){
+		for (int j = 0; j < dstWidth; ++j){
+			unsigned char *p;
+			p = (unsigned char *)(pBmpBuf2 + lineByte2*i + j);
+			(*p) = 255;
+		}
+	}
+	int x = 0;
+	int y = 0;
+	for(int i = 0; i < height; ++i){
+		for(int j = 0; j < width; ++j){
+			unsigned char *p1, *p2;
+			// x = round(double(lx*j));
+			// y = round(double(ly*i));
+			x = round(double(k*j));
+			y = round(double(k*i));
+			p1 = (unsigned char *)(pBmpBuf + i*lineByte + j);
+			p2 = (unsigned char *)(pBmpBuf2 + y*lineByte2 + x);
+			(*p2) = (*p1);
+		}
+	}
+ 
+	FILE *fpo = fopen("C:\\Users\\leong\\Desktop\\bmp_exam\\output\\output.bmp", "wb");
+	if (fpo == 0)
+		return 0;
+	BITMAPFILEHEADER dstFileHead;
+	dstFileHead.bfOffBits = 14 + 40 + pColorTableSize;
+	dstFileHead.bfReserved1 = 0;
+	dstFileHead.bfReserved2 = 0;
+	dstFileHead.bfSize = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+pColorTableSize + lineByte2*dstHeight;
+	dstFileHead.bfType = 0x4D42;
+	fwrite(&dstFileHead, sizeof(dstFileHead), 1, fpo);
+ 
+	BITMAPINFOHEADER dstInfoHead;
+	dstInfoHead.biBitCount = biCount;
+	dstInfoHead.biClrImportant = 0;
+	dstInfoHead.biClrUsed = 0;
+	dstInfoHead.biCompression = 0;
+	dstInfoHead.biHeight = dstHeight;
+	dstInfoHead.biPlanes = 1;
+	dstInfoHead.biSize = 40;
+	dstInfoHead.biSizeImage = lineByte2*dstHeight;
+	dstInfoHead.biWidth = dstWidth;
+	dstInfoHead.biXPelsPerMeter = 0;
+	dstInfoHead.biYPelsPerMeter = 0;
+	fwrite(&dstInfoHead, sizeof(BITMAPINFOHEADER), 1, fpo);
+ 
+	fwrite(pColorTable, sizeof(RGBQUAD), 256, fpo);
+	fwrite(pBmpBuf2, lineByte2*dstHeight, 1, fp);
+	fclose(fpo);
+ 
+	system("pause");
+	return 0;
+}
\ No newline at end of file
diff --git a/zoom.exe b/zoom.exe
new file mode 100644
index 0000000..12bbca9
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