I'm getting corrupt output when writing a GeoTiff using GDAL API (v1.10 - C++). The raster geotransform is correct, the block is written in the correct position but the pixels are written at random positions and values within the block.
Example: http://i.imgur.com/mntnAfK.png
Method: Open a GDAL Raster --> copy projection info & size --> create output GeoTiff --> write a block from array at offset.
Code:
//Open the input DEM
const char* demFName = "/Users/mount.dem";
const char* outFName = "/Users/geodata/out_test.tif";
auto poDataset = ioUtils::openDem(demFName);
double adfGeoTransform[6];
poDataset->GetGeoTransform( adfGeoTransform );
//Setup driver
const char *pszFormat = "GTiff";
GDALDriver *poDriver;
poDriver = GetGDALDriverManager()->GetDriverByName(pszFormat);
char *pszSRS_WKT = NULL;
GDALRasterBand *poBand;
//Get size from input Raster
int xSize = poDataset->GetRasterXSize();
int ySize = poDataset->GetRasterYSize();
//Set output Dataset
GDALDataset *poDstDS;
char **papszOptions = NULL;
//Create output geotiff
poDstDS = poDriver->Create( outFName, xSize, ySize, 1, GDT_Byte, papszOptions );
//Get the geotrans from the input geotrans
poDataset->GetGeoTransform( adfGeoTransform );
poDstDS->SetGeoTransform( adfGeoTransform );
poDstDS->SetProjection( poDataset->GetProjectionRef() );
//Create some data to write
unsigned char rData[512*512];
//Assign some values other than 0
for (int col=0; col < 512; col++){
for (int row=0; row < 512; row++){
rData[col*row] = 50;
}
}
//Write some data
poBand = poDstDS->GetRasterBand(1);
poBand->RasterIO( GF_Write, 200, 200, 512, 512,
rData, 512, 512, GDT_Byte, 0, 0 );
//Close
GDALClose( (GDALDatasetH) poDstDS );
std::cout << "Done" << std::endl;
Any ideas / pointers where I'm going wrong much appreciated.
Always something trivial...
rData[row*512+col] = 50
Qudos to Even Rouault on osgeo.
Related
I'm currently working with gdal api C/C++ and I'm facing an issue with gdal warp region to buffer functionality (WarpRegionToBuffer).
When my destination dataset is not strictly contained in the frame of my source dataset, the area where there should be no data values is filled with random data (see out_code.tif enclosed). However gdalwarp command line functionality, which also uses WarpRegionToBuffer function, does not seem to have this problem.
1/ Here is the code I use:
#include <iostream>
#include <string>
#include <vector>
#include "gdal.h"
#include "gdalwarper.h"
#include "cpl_conv.h"
int main(void)
{
std::string pathSrc = "in.dt1";
//these datas will be provided by command line
std::string pathDst = "out_code.tif";
double resolutionx = 0.000833333;
double resolutiony = 0.000833333;
//destination corner coordinates: top left (tl) bottom right (br)
float_t xtl = -1;
float_t ytl = 45;
float_t xbr = 2;
float_t ybr = 41;
//tile size defined by user
int tilesizex = 256;
int tilesizey = 256;
float width = std::ceil((xbr - xtl)/resolutionx);
float height = std::ceil((ytl - ybr)/resolutiony);
double adfDstGeoTransform[6] = {xtl, resolutionx, 0, ytl, 0, -resolutiony};
GDALDatasetH hSrcDS, hDstDS;
// Open input file
GDALAllRegister();
hSrcDS = GDALOpen(pathSrc.c_str(), GA_ReadOnly);
GDALDataType eDT = GDALGetRasterDataType(GDALGetRasterBand(hSrcDS,1));
// Create output file, using same spatial reference as input image, but new geotransform
GDALDriverH hDriver = GDALGetDriverByName( "GTiff" );
hDstDS = GDALCreate( hDriver, pathDst.c_str(), width, height, GDALGetRasterCount(hSrcDS), eDT, NULL );
OGRSpatialReference oSRS;
char *pszWKT = NULL;
//force geo projection
oSRS.SetWellKnownGeogCS( "WGS84" );
oSRS.exportToWkt( &pszWKT );
GDALSetProjection( hDstDS, pszWKT );
//Fetches the coefficients for transforming between pixel/line (P,L) raster space,
//and projection coordinates (Xp,Yp) space.
GDALSetGeoTransform( hDstDS, adfDstGeoTransform );
// Setup warp options
GDALWarpOptions *psWarpOptions = GDALCreateWarpOptions();
psWarpOptions->hSrcDS = hSrcDS;
psWarpOptions->hDstDS = hDstDS;
psWarpOptions->nBandCount = 1;
psWarpOptions->panSrcBands = (int *) CPLMalloc(sizeof(int) * psWarpOptions->nBandCount );
psWarpOptions->panSrcBands[0] = 1;
psWarpOptions->panDstBands = (int *) CPLMalloc(sizeof(int) * psWarpOptions->nBandCount );
psWarpOptions->panDstBands[0] = 1;
psWarpOptions->pfnProgress = GDALTermProgress;
//these datas will be calculated in order to warp tile by tile
//current tile size
int cursizex = 0;
int cursizey = 0;
double nbtilex = std::ceil(width/tilesizex);
double nbtiley = std::ceil(height/tilesizey);
int starttilex = 0;
int starttiley = 0;
// Establish reprojection transformer
psWarpOptions->pTransformerArg =
GDALCreateGenImgProjTransformer(hSrcDS,
GDALGetProjectionRef(hSrcDS),
hDstDS,
GDALGetProjectionRef(hDstDS),
FALSE, 0.0, 1);
psWarpOptions->pfnTransformer = GDALGenImgProjTransform;
// Initialize and execute the warp operation on region
GDALWarpOperation oOperation;
oOperation.Initialize(psWarpOptions);
for (int ty = 0; ty < nbtiley; ty++) {
//handle last tile size
//if it last tile change size otherwise keep tilesize
for (int tx = 0; tx < nbtilex; tx++) {
//if it last tile change size otherwise keep tilesize
starttiley = ty * tilesizey;
starttilex = tx * tilesizex;
cursizex = std::min(starttilex + tilesizex, (int)width) - starttilex;
cursizey = std::min(starttiley + tilesizey, (int)height) - starttiley;
float * buffer = new float[cursizex*cursizey];
memset(buffer, 0, cursizex*cursizey);
//warp source
CPLErr ret = oOperation.WarpRegionToBuffer(
starttilex, starttiley, cursizex, cursizey,
buffer,
eDT);
if (ret != 0) {
CEA_SIMONE_ERROR(CPLGetLastErrorMsg());
throw std::runtime_error("warp error");
}
//write the fuzed tile in dest
ret = GDALRasterIO(GDALGetRasterBand(hDstDS,1),
GF_Write,
starttilex, starttiley, cursizex, cursizey,
buffer, cursizex, cursizey,
eDT,
0, 0);
if (ret != 0) {
CEA_SIMONE_ERROR("raster io write error");
throw std::runtime_error("raster io write error");
}
delete(buffer);
}
}
// Clean memory
GDALDestroyGenImgProjTransformer( psWarpOptions->pTransformerArg );
GDALDestroyWarpOptions( psWarpOptions );
GDALClose( hDstDS );
GDALClose( hSrcDS );
return 0;
}
The result:
output image of previous sample of code (as png, as I can't enclose TIF img)
The GdalWarp command line:
gdalwarp -te -1 41 2 45 -tr 0.000833333 0.000833333 in.dt1 out_cmd_line.tif
The command line result:
output image of previous command line (as png, as I can't enclose TIF img)
Can you please help me find what is wrong with my use of GDAL C/C++ API in order to have a similar behaviour as gdalwarp command line? There is probably an algorithm in gdalwarp that computes a mask of useful pixels in destination frame before calling WarpRegionToBuffer, but I didn't find it.
I would really appreciate help on this problem!
Best regards
Here is a code that decodes a WebM frame and put them in a buffer
image->planes[p] = pointer to the top left pixel
image->linesize[p] = strides betwen rows
framesArray = vector of unsigned char*
while ( videoDec->getImage(*image) == VPXDecoder::NO_ERROR)
{
const int w = image->getWidth(p);
const int h = image->getHeight(p);
int offset = 0;
for (int y = 0; y < h; y++)
{
// fwrite(image->planes[p] + offset, 1, w, pFile);
for(int i=0;i<w;i++){
framesArray.at(count)[i+(w*y)] = *(image->planes[p]+offset+ i) ;
}
offset += image->linesize[p];
}
}
.............................
How can I write intro buffer line by line not pixel by pixel or optimize the writing of frame intro buffer?
if the source image and destination buffer share the same Width, Height and bit per pixel, you can use std::copy to copy the whole image into it.
std::copy(image->planes[p] + offset, image->planes[p] + (image->getHeight(p) * image->linesize[p], framesArray.begin()) ;
if it is same bit per pixel but different width and height, you can use std::copy by line.
I am trying to extract frames from a stream which I create with Gstreamer and trying to save them with FreeImage or QImage ( this one is for testing ).
GstMapInfo bufferInfo;
GstBuffer *sampleBuffer;
GstStructure *capsStruct;
GstSample *sample;
GstCaps *caps;
int width, height;
const int BitsPP = 32;
/* Retrieve the buffer */
g_signal_emit_by_name (sink, "pull-sample", &sample);
if (sample) {
sampleBuffer = gst_sample_get_buffer(sample);
gst_buffer_map(sampleBuffer,&bufferInfo,GST_MAP_READ);
if (!bufferInfo.data) {
g_printerr("Warning: could not map GStreamer buffer!\n");
throw;
}
caps = gst_sample_get_caps(sample);
capsStruct= gst_caps_get_structure(caps,0);
gst_structure_get_int(capsStruct,"width",&width);
gst_structure_get_int(capsStruct,"height",&height);
auto bitmap = FreeImage_Allocate(width, height, BitsPP,0,0,0);
memcpy( FreeImage_GetBits( bitmap ), bufferInfo.data, width * height * (BitsPP/8));
// int pitch = ((((BitsPP * width) + 31) / 32) * 4);
// auto bitmap = FreeImage_ConvertFromRawBits(bufferInfo.data,width,height,pitch,BitsPP,0, 0, 0);
FreeImage_FlipHorizontal(bitmap);
bitmap = FreeImage_RotateClassic(bitmap,180);
static int id = 0;
std::string name = "/home/stadmin/pic/sample" + std::to_string(id++) + ".png";
#ifdef FREE_SAVE
FreeImage_Save(FIF_PNG,bitmap,name.c_str());
#endif
#ifdef QT_SAVE
//Format_ARGB32
QImage image(bufferInfo.data,width,height,QImage::Format_ARGB32);
image.save(QString::fromStdString(name));
#endif
fibPipeline.push(bitmap);
gst_sample_unref(sample);
gst_buffer_unmap(sampleBuffer, &bufferInfo);
return GST_FLOW_OK;
The color output in FreeImage are totally wrong like when Qt - Format_ARGB32 [ greens like blue or blues like oranges etc.. ] but when I test with Qt - Format_RGBA8888 I can get correct output. I need to use FreeImage and I wish to learn how to correct this.
Since you say Qt succeeds using Format_RGBA8888, I can only guess: the gstreamer frame has bytes in RGBA order while FreeImage expects ARGB.
Quick fix:
//have a buffer the same length of the incoming bytes
size_t length = width * height * (BitsPP/8);
BYTE * bytes = (BYTE *) malloc(length);
//copy the incoming bytes to it, in the right order:
int index = 0;
while(index < length)
{
bytes[index] = bufferInfo.data[index + 2]; //B
bytes[index + 1] = bufferInfo.data[index + 1]; //G
bytes[index + 2] = bufferInfo.data[index]; //R
bytes[index + 3] = bufferInfo.data[index + 3]; //A
index += 4;
}
//fill the bitmap using the buffer
auto bitmap = FreeImage_Allocate(width, height, BitsPP,0,0,0);
memcpy( FreeImage_GetBits( bitmap ), bytes, length);
//don't forget to
free(bytes);
My 2D texture loader works fine if my texture dimensions are power-of-two, but when they are not, the texture data displays as skewed. How do I fix this? I assume the issue has something to do with memory alignment and row pitch. Here's relevant parts of my loader code:
VkMemoryRequirements memReqs;
vkGetImageMemoryRequirements( GfxDeviceGlobal::device, mappableImage, &memReqs );
VkMemoryAllocateInfo memAllocInfo = {};
memAllocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
memAllocInfo.pNext = nullptr;
memAllocInfo.memoryTypeIndex = 0;
memAllocInfo.allocationSize = memReqs.size;
GetMemoryType( memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, &memAllocInfo.memoryTypeIndex );
VkDeviceMemory mappableMemory;
err = vkAllocateMemory( GfxDeviceGlobal::device, &memAllocInfo, nullptr, &mappableMemory );
CheckVulkanResult( err, "vkAllocateMemory in Texture2D" );
err = vkBindImageMemory( GfxDeviceGlobal::device, mappableImage, mappableMemory, 0 );
CheckVulkanResult( err, "vkBindImageMemory in Texture2D" );
VkImageSubresource subRes = {};
subRes.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
subRes.mipLevel = 0;
subRes.arrayLayer = 0;
VkSubresourceLayout subResLayout;
vkGetImageSubresourceLayout( GfxDeviceGlobal::device, mappableImage, &subRes, &subResLayout );
void* mapped;
err = vkMapMemory( GfxDeviceGlobal::device, mappableMemory, 0, memReqs.size, 0, &mapped );
CheckVulkanResult( err, "vkMapMemory in Texture2D" );
const int bytesPerPixel = 4;
std::size_t dataSize = bytesPerPixel * width * height;
std::memcpy( mapped, data, dataSize );
vkUnmapMemory( GfxDeviceGlobal::device, mappableMemory );
The VkSubresourceLayout, which you obtained from vkGetImageSubresourceLayout will contain the pitch of the texture in the rowPitch member. It's more than likely not equal to the width, thus, when you do a memcpy of the entire data block, you're copying relevant data into the padding section of the texture.
Instead you will need to memcpy row-by-row, skipping the padding memory in the mapped texture:
const int bytesPerPixel = 4;
std::size_t dataRowSize = bytesPerPixel * width;
char* mappedBytes = (char*)mapped;
for(int i = 0; i < height; ++i)
{
std::memcpy(mapped, data, dataSize);
mappedBytes += rowPitch;
data += dataRowSize;
}
(this code assumes data is a char * as well - its declaration wasn't given)
for(int i = 0; i < height; ++i)
{
std::memcpy(mappedBytes, data, dataRowSize);
mappedBytes += layout.rowPitch;
data += dataRowSize;
}
I have a TGA file and a library that allready has everything that I need to read TGA and use them.
This class has a method called pixels(), that returns a pointer that is pointed to the memory area where pixel are stored as RGBRGBRGB...
My question is, how can I take the pixel value?
Cause if I make something like this:
img.load("foo.tga");
printf ("%i", img.pixels());
It gives back to me what is proprably the address.
I've found this code on this site:
struct Pixel2d
{
static const int SIZE = 50;
unsigned char& operator()( int nCol, int nRow, int RGB)
{
return pixels[ ( nCol* SIZE + nRow) * 3 + RGB];
}
unsigned char pixels[SIZE * SIZE * 3 ];
};
int main()
{
Pixel2d p2darray;
glReadPixels(50,50, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, &p.pixels);
for( int i = 0; i < Pixel2d::SIZE ; ++i )
{
for( int j = 0; j < Pixel2d::SIZE ; ++j )
{
unsigned char rpixel = p2darray(i , j , 0);
unsigned char gpixel = p2darray(i , j , 1);
unsigned char bpixel = p2darray(i , j , 2);
}
}
}
I think that It can work great for me, but how can I tell the program to read from my img?
Tga supports different pixel depths. And we don't know what library you're using. But generally speaking pixels() should return a pointer to a buffer containing pixels. Say for sake of argument it unpacks the pixels into 8-bit per channel subpixels, then each pixel is represented by 3 bytes.
So to access a pixel at a given offset in the buffer:
const u8* pixelBuffer = img.pixels():
u8 red = pixelBuffer[(offset*3)+0];
u8 green = pixelBuffer[(offset*3)+1];
u8 blue = pixelBuffer[(offset*3)+2];
If you know the width of the image buffer then you can get a pixel by its x and y coordinates:
u8 red = pixelBuffer[((x+(y*width))*3)+0];