the problem has been solved by using CsXMpToolKit.dll ,which is the best option to fetch the metadat from any type of file.
To change the metatags of PNG Image files
Вопрос
I am using PngCs dll to fetch the chunk data for Png image file in asp.net, I am able to do that but now I want to update the chunk data for that PNG.
I used PngWriter but it is creating whole new file without inheriting chunk data.
PngReader pngr = FileHelper.CreatePngReader(path);
pngr.GetMetadata().GetTxtForKey(PngChunkITXT.KEY_Title);
Response.Write(pngr.GetMetadata().GetTxtForKey(PngChunkITXT.KEY_Title));
Below code is for writing new Png Image through PngWriter ,I want embed new itxt chunk while creating new file.
PngReader pngr = FileHelper.CreatePngReader(origFilename); // or you can use the constructor
PngWriter pngw = FileHelper.CreatePngWriter(destFilename, pngr.ImgInfo, true); // idem
Console.WriteLine(pngr.ToString()); // just information
int chunkBehav = ChunkCopyBehaviour.COPY_ALL_SAFE; // tell to copy all 'safe' chunks
pngw.CopyChunksFirst(pngr, chunkBehav); // copy some metadata from reader
for (int row = 0; row < pngr.ImgInfo.Rows; row++)
{
ImageLine l1 = pngr.ReadRowInt(row); // format: RGBRGB... or RGBARGBA...
pngw.WriteRow(l1, row);
}
pngw.CopyChunksLast(pngr, chunkBehav); // metadata after the image pixels? can happen
pngw.End(); // dont forget this
pngr.End();
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Решение 2
Другие советы
Try this
PngReader pngr = FileHelper.CreatePngReader(origFilename);
PngWriter pngw = FileHelper.CreatePngWriter(destFilename, pngr.ImgInfo, true);
pngw.CopyChunksFirst(pngr, ChunkCopyBehaviour.COPY_ALL);
pngw.GetMetadata().SetText(myKey, myText,false,false); // provide your own data
for (int row = 0; row < pngr.ImgInfo.Rows; row++) {
ImageLine l1 = pngr.ReadRowInt(row);
pngw.WriteRow(l1, row);
}
pngw.CopyChunksLast(pngr, ChunkCopyBehaviour.COPY_ALL);
pngw.End(); // dont forget this
pngr.End();
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