利用FreeImage将gif图像转为opencv中的Mat
【摘要】
原文：http://www.cnblogs.com/monkeyhey/p/3927857.html
网上有将gif转为iplimg的版本，只是用惯了C++的接口，所以就写了个转Mat的版本，代码比较简单
一、读文件
1 int MatFun::gif2Mat(char* data, size_t dataSize, vector<Mat...
原文：http://www.cnblogs.com/monkeyhey/p/3927857.html
网上有将gif转为iplimg的版本，只是用惯了C++的接口，所以就写了个转Mat的版本，代码比较简单
一、读文件
1 int MatFun::gif2Mat(char* data, size_t dataSize, vector<Mat>& gifImgs, Mat& singleImg) 2 { 3 /* initialise 4 ->open memory 5 ->getImageType 6 ->load bitmaps 7 ->bitmaps to Mat 8 ->free all resource 9 */ 10 // condition1: data is not null 11 if (NULL == data || dataSize == 0) 12 return -1; 13 FreeImage_Initialise(); 14 FIMEMORY* memory = FreeImage_OpenMemory((BYTE*)data, dataSize); 15 if (NULL==memory) 16 { 17 FreeImage_DeInitialise(); //condition 2: memory is not null 18 } 19 20 FREE_IMAGE_FORMAT fif = FreeImage_GetFileTypeFromMemory(memory); 21 if (FIF_UNKNOWN == fif) //condition 3: type of image should be know 22 { 23 fprintf(stderr, "unknown type of image"); 24 if (NULL != memory) FreeImage_CloseMemory(memory); 25 FreeImage_DeInitialise(); 26 return -1; 27 } 28 else if (FIF_GIF != fif) //condition 4: type of image should be GIF 29 { 30 if (NULL != memory) FreeImage_CloseMemory(memory); 31 FreeImage_DeInitialise(); 32 return 0; 33 } 34 35 FIMULTIBITMAP * fiBmp = FreeImage_LoadMultiBitmapFromMemory(fif, memory, GIF_DEFAULT); 36 if (NULL==fiBmp) 37 { 38 if (NULL != memory) FreeImage_CloseMemory(memory); //condition 5: bitmaps is not null 39 FreeImage_DeInitialise(); 40 return -1; 41 } 42 43 int num = FreeImage_GetPageCount(fiBmp); 44 45 for (int i = 0; i < num; i++) 46 { 47 if (i==0 || i==2) 48 { 49 FIBITMAP *mfibmp = FreeImage_LockPage(fiBmp, i); 50 if (mfibmp) 51 { 52 Mat dst = bitMap2Mat(mfibmp, fif); 53 FreeImage_UnlockPage(fiBmp, mfibmp, false); 54 if (dst.empty()) 55 { 56 if (NULL != memory) FreeImage_CloseMemory(memory); 57 if (NULL != fiBmp) FreeImage_CloseMultiBitmap(fiBmp, GIF_DEFAULT); 58 FreeImage_DeInitialise(); 59 return -1; 60 } 61 gifImgs.push_back(dst); 62 dst.release(); 63 } 64 } 65 } 66 67 if (NULL != memory) 68 FreeImage_CloseMemory(memory); 69 if (NULL != fiBmp) 70 FreeImage_CloseMultiBitmap(fiBmp); 71 FreeImage_DeInitialise(); 72 73 return 0; 74 }
这部分其实功能很简单，代码里面大部分都是检查，实际执行就初始化、打开内存、内存中读bitmap这几步。
二、gif转Mat
Mat MatFun::bitMap2Mat(FIBITMAP* fiBmp, const FREE_IMAGE_FORMAT &fif) { if (NULL == fiBmp || FIF_GIF != fif) return Mat(); int width = FreeImage_GetWidth(fiBmp); int height = FreeImage_GetHeight(fiBmp); BYTE intensity; BYTE* pIntensity = &intensity; if(FreeImage_GetBPP(fiBmp) !=8) fiBmp = FreeImage_ConvertTo8Bits(fiBmp); //必须转化为8bit RGBQUAD* pixels = new RGBQUAD; pixels = FreeImage_GetPalette(fiBmp); Mat img=Mat::zeros(height, width, CV_8UC3); uchar* p; for (int i = 0; i < height; i++) { p = img.ptr<uchar>(i); for (int j = 0; j < width; j++) { FreeImage_GetPixelIndex(fiBmp, j, i, pIntensity); p[3 * j] = pixels[intensity].rgbBlue; p[3 * j + 1] = pixels[intensity].rgbGreen; p[3 * j + 2] = pixels[intensity].rgbRed; } } return img; }
具体的将byte像素转化为mat里面的像素值即可，注意rgb图像的Mat里是一个像素包含三通道的值，知道这点，代码就很好理解了。
-
#include <FreeImage.h>
-
#include <opencv2\opencv.hpp>
-
using namespace cv;
-
-
void FI2MAT(FIBITMAP* src, Mat& dst)
-
{
-
//FIT_BITMAP //standard image : 1 - , 4 - , 8 - , 16 - , 24 - , 32 - bit
-
//FIT_UINT16 //array of unsigned short : unsigned 16 - bit
-
//FIT_INT16 //array of short : signed 16 - bit
-
//FIT_UINT32 //array of unsigned long : unsigned 32 - bit
-
//FIT_INT32 //array of long : signed 32 - bit
-
//FIT_FLOAT //array of float : 32 - bit IEEE floating point
-
//FIT_DOUBLE //array of double : 64 - bit IEEE floating point
-
//FIT_COMPLEX //array of FICOMPLEX : 2 x 64 - bit IEEE floating point
-
//FIT_RGB16 //48 - bit RGB image : 3 x 16 - bit
-
//FIT_RGBA16 //64 - bit RGBA image : 4 x 16 - bit
-
//FIT_RGBF //96 - bit RGB float image : 3 x 32 - bit IEEE floating point
-
//FIT_RGBAF //128 - bit RGBA float image : 4 x 32 - bit IEEE floating point
-
-
int bpp = FreeImage_GetBPP(src);
-
FREE_IMAGE_TYPE fit = FreeImage_GetImageType(src);
-
-
int cv_type = -1;
-
int cv_cvt = -1;
-
-
switch (fit)
-
{
-
case FIT_UINT16: cv_type = DataType<ushort>::type; break;
-
case FIT_INT16: cv_type = DataType<short>::type; break;
-
case FIT_UINT32: cv_type = DataType<unsigned>::type; break;
-
case FIT_INT32: cv_type = DataType<int>::type; break;
-
case FIT_FLOAT: cv_type = DataType<float>::type; break;
-
case FIT_DOUBLE: cv_type = DataType<double>::type; break;
-
case FIT_COMPLEX: cv_type = DataType<Complex<double>>::type; break;
-
case FIT_RGB16: cv_type = DataType<Vec<ushort, 3>>::type; cv_cvt = COLOR_RGB2BGR; break;
-
case FIT_RGBA16: cv_type = DataType<Vec<ushort, 4>>::type; cv_cvt = COLOR_RGBA2BGRA; break;
-
case FIT_RGBF: cv_type = DataType<Vec<float, 3>>::type; cv_cvt = COLOR_RGB2BGR; break;
-
case FIT_RGBAF: cv_type = DataType<Vec<float, 4>>::type; cv_cvt = COLOR_RGBA2BGRA; break;
-
case FIT_BITMAP:
-
switch (bpp) {
-
case 8: cv_type = DataType<Vec<uchar, 1>>::type; break;
-
case 16: cv_type = DataType<Vec<uchar, 2>>::type; break;
-
case 24: cv_type = DataType<Vec<uchar, 3>>::type; break;
-
case 32: cv_type = DataType<Vec<uchar, 4>>::type; break;
-
default:
-
// 1, 4 // Unsupported natively
-
cv_type = -1;
-
}
-
break;
-
default:
-
// FIT_UNKNOWN // unknown type
-
dst = Mat(); // return empty Mat
-
return;
-
}
-
-
int width = FreeImage_GetWidth(src);
-
int height = FreeImage_GetHeight(src);
-
int step = FreeImage_GetPitch(src);
-
-
if (cv_type >= 0) {
-
dst = Mat(height, width, cv_type, FreeImage_GetBits(src), step);
-
if (cv_cvt > 0)
-
{
-
cvtColor(dst, dst, cv_cvt);
-
}
-
}
-
else {
-
-
vector<uchar> lut;
-
int n = pow(2, bpp);
-
for (int i = 0; i < n; ++i)
-
{
-
lut.push_back(static_cast<uchar>((255 / (n - 1))*i));
-
}
-
-
FIBITMAP* palletized = FreeImage_ConvertTo8Bits(src);
-
BYTE* data = FreeImage_GetBits(src);
-
for (int r = 0; r < height; ++r) {
-
for (int c = 0; c < width; ++c) {
-
dst.at<uchar>(r, c) = saturate_cast<uchar>(lut[data[r*step + c]]);
-
}
-
}
-
}
-
-
flip(dst, dst, 0);
-
}
-
-
int main()
-
{
-
FreeImage_Initialise();
-
FREE_IMAGE_FORMAT format = FreeImage_GetFileType("path_to_image", 0);
-
FIBITMAP* fi_image = FreeImage_Load(format, "path_to_image");
-
-
Mat cv_img;
-
FI2MAT(fi_image, cv_img);
-
-
return 0;
-
}
文章来源: blog.csdn.net，作者：网奇，版权归原作者所有，如需转载，请联系作者。
原文链接：blog.csdn.net/jacke121/article/details/60569972
【版权声明】本文为华为云社区用户转载文章，如果您发现本社区中有涉嫌抄袭的内容，欢迎发送邮件进行举报，并提供相关证据，一经查实，本社区将立刻删除涉嫌侵权内容，举报邮箱：
cloudbbs@huaweicloud.com
- 点赞
- 收藏
- 关注作者
评论（0）