Hermann,<div><br></div><div>You're right the size difference is because of PNG8 or PNG24.</div><div><br></div><div>I'm now on the gdal_warp track again. But I can't produce a PNG file. When I use -ot PNG I get this list of supported file formats:</div>
<div><div> VRT: Virtual Raster</div><div> GTiff: GeoTIFF</div><div> NITF: National Imagery Transmission Format</div><div> HFA: Erdas Imagine Images (.img)</div><div> ELAS: ELAS</div><div> MEM: In Memory Raster</div>
</div><div><div> BMP: MS Windows Device Independent Bitmap</div><div> PCIDSK: PCIDSK Database File</div><div> ILWIS: ILWIS Raster Map</div><div> SGI: SGI Image File Format 1.0</div><div> Leveller: Leveller heightfield</div>
<div> Terragen: Terragen heightfield</div><div> ERS: ERMapper .ers Labelled</div><div> JP2ECW: ERMapper JPEG2000</div><div> RMF: Raster Matrix Format</div><div> RST: Idrisi Raster A.1</div><div> INGR: Intergraph Raster</div>
<div> GSBG: Golden Software Binary Grid (.grd)</div><div> PNM: Portable Pixmap Format (netpbm)</div><div> ENVI: ENVI .hdr Labelled</div><div> EHdr: ESRI .hdr Labelled</div><div> PAux: PCI .aux Labelled</div><div> MFF: Vexcel MFF Raster</div>
<div> MFF2: Vexcel MFF2 (HKV) Raster</div><div> BT: VTP .bt (Binary Terrain) 1.3 Format</div><div> IDA: Image Data and Analysis</div><div> ADRG: ARC Digitized Raster Graphics</div><div> SAGA: SAGA GIS Binary Grid (.sdat)</div>
</div><div><br></div><div>Does this mean I haven't build my GDAL properly? If not can you give me a hint on how to enable png support in the make files?</div><div><br></div><div>Thanks,</div><div><br></div><div>Paul</div>
<div><br></div><div><br><div class="gmail_quote">2010/10/26 Hermann Peifer <span dir="ltr"><<a href="mailto:peifer@gmx.eu">peifer@gmx.eu</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On 25/10/2010 11:17, Paul Meems wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi list,<br>
<br>
I've got several png files with worldfiles.<br>
I need them in another projection (28992 --> 3785).<br>
I'm using gdalwarp to reproject to a tiff file and then I use<br>
gdal_translate to create a png file again.<br>
My original png file is about 25 kB, the warped tiff is over 2MB and the<br>
translated png file is over 80 kB.<br>
<br>
</blockquote>
<br></div>
I am not quite sure why you don't use -of png to save the creation of the intermediate tiff file. You might also be able to use -of byte which creates an 8 bit PNG (if this format is sufficient for your purpose).<br>
<br>
The size difference 20k vs 80k could be due to the fact that the source file is PNG8 and the generated file is PNG24. There may be other reasons, though.<br><font color="#888888">
<br>
Hermann<br>
</font></blockquote></div><br></div>