Quote:A grayscale png only has one channel per pixel (or two if it is grayscale with alpha). You load it using libpng or some general image loading library that uses libpng internally.
Original post by Dragon_Strike
ok so its a 16bit greyscale image which means it has 16bits per channel (48bit image)... how do i load a 16bit greyscale png into memory?
or is there a way/program which can convert this into a 24bit color image where it sets the 16bit value as two 8 bit color values...
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Original post by Kalidor Quote:A grayscale png only has one channel per pixel (or two if it is grayscale with alpha). You load it using libpng or some general image loading library that uses libpng internally.
Original post by Dragon_Strike
ok so its a 16bit greyscale image which means it has 16bits per channel (48bit image)... how do i load a 16bit greyscale png into memory?
or is there a way/program which can convert this into a 24bit color image where it sets the 16bit value as two 8 bit color values...
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Original post by hplus0603
If you can't read a PNG image using the documentation for the library, then you probably need to step back from your current problem and work a little bit on that piece of the code. It's a fairly easy-to-use library, and comes with sample code.
To convert between image formats, I usually use Photoshop. There are free, downloadable trials on the Adobe web site. Another program (which is free) that can do it is The Gimp, but I don't know how well it supports 16 bits per pixel.
unsigned short* HeightMap; char* szFilename = "temp.raw"; FILE *fp = NULL; fp = fopen(szFilename, "rb"); HeightMap = new unsigned short[ m_iSize*m_iSize]; fread(HeightMap, m_iSize*m_iSize*sizeof(unsigned short), 1, fp); fclose(fp);//Getvalue function inline float GetHeight(int x, int z) { return HeightMap[x+z*m_iSize];//m_HeightMap.Get16RedColor(x, z); }Quote:
Original post by PlayerX
That could be Photoshop's PNG bugs. I think its 16-bit grayscale handling is broken. Try the SuperPNG plugin and see if that improves things for you.
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Original post by PlayerX
Hmmm, well, hard to tell where the problem is without seeing your datasets and code.
Just to double check, did you put the SuperPNG.8bi file into the Plug-Ins\Adobe Photoshop Only\File Formats directory of Photoshop and are you seeing the option to save out SuperPNG(*.PNG) files?
unsigned short* HeightMap; char* szFilename = "temp.raw"; FILE *fp = NULL; fp = fopen(szFilename, "rb"); HeightMap = new unsigned short[ m_iSize*m_iSize]; fread(HeightMap, m_iSize*m_iSize*sizeof(unsigned short), 1, fp); fclose(fp);//Getvalue function inline float GetHeight(int x, int z) { return HeightMap[x+z*m_iSize]; }t_Buffer *Verts, *Indices;struct s_Sample { t_Vec3 Vertex; t_Vec3 Normal;} TerrainMap[1025*1025];ulong Index[1024 * 1024 * 6];void terrtest(void) { ushort * Heights; void * File; ulong FileSize; int x, y, i; float fx, fy; struct s_Sample * sm; ulong * ind; FileSize = FileLoad(&File, "ps_height_1k.raw"); if (!File) return; Heights = (ushort *) File; sm = TerrainMap; fy = 0; for (y=0; y<1025; y++) { fx = 0; for (x=0; x<1025; x++) { sm->Vertex.x = fx; sm->Vertex.y = fy; sm->Vertex.z = (float)*Heights++; sm++; fx += 1000.0f; } fy += 1000.0f; } MemFree(File); // Doesn't do edge normals properly, but this is just test code, so... for (y=1; y<1024; y++) { for (x=1; x<1024; x++) { sm = &TerrainMap[x + y * 1025]; sm->Normal.x = TerrainMap[(x - 1) + y * 1025].Vertex.z - TerrainMap[(x + 1) + y * 1025].Vertex.z; sm->Normal.y = TerrainMap[x + (y - 1) * 1025].Vertex.z - TerrainMap[x + (y + 1) * 1025].Vertex.z; sm->Normal.z = 2.0f * 1000.0f; VecNorm(&sm->Normal, &sm->Normal); } } Verts = BufferNew(TerrainMap, sizeof(TerrainMap), BUFFER_VERTEX, 0); ind = Index; for (y=0; y<1024; y++) { i = y * 1025; for (x=0; x<1024; x++) { *ind++ = i; *ind++ = i + 1; *ind++ = i + 1025; *ind++ = i + 1; *ind++ = i + 1026; *ind++ = i + 1025; i++; } } Indices = BufferNew(Index, sizeof(Index), BUFFER_INDEX, 0);}void terrrender(void) { if (!Verts || !Indices) return; glEnable(GL_LIGHTING); glColor4f(1, 1, 1, 1); glShadeModel(GL_SMOOTH); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_NORMAL_ARRAY); glBindBuffer(GL_ARRAY_BUFFER, Verts->Buffer); glVertexPointer(3, GL_FLOAT, sizeof(struct s_Sample), 0); glNormalPointer(GL_FLOAT, sizeof(struct s_Sample), (void *)sizeof(t_Vec3)); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, Indices->Buffer); glDrawElements(GL_TRIANGLES, 1024*1024*6, GL_UNSIGNED_INT, 0);}
HeightMap = new float [257*257]; //m_HeightMap.LoadData("../Data/256h.tga"); void *File = NULL; File = fopen("../Data/256h.raw", "rb"); if (!File) return; unsigned short* Heights; Heights = (unsigned short *) File; for (int y=0; y<257; y++) { for (int x=0; x<257; x++) { HeightMap[x+y*257] = (float)*Heights++; } } free(File); FILE *fp = NULL; fp = fopen("../Data/ps_height_1k.raw", "rb"); HeightMap = new unsigned short[ 1025*1025]; fread(HeightMap, 1025*1025*sizeof(unsigned short), 1, fp); fclose(fp); inline float GetHeight(int x, int z) { return HeightMap[x+z*1025]/650; }Quote:
Original post by Dragon_Strike
thx alot... ill look at it... te download an dpicture u posted doesnt work though... the way u open the file doest seem to work for me... u got ur own function? "FileLoad" ?
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