How to use titiler ?

[StringKe]

1. I have a 4000x4000 size png image
2. I need to move it to start at a certain latitude and longitude (leftTop) and end at a longitude and latitude (rightBottom)

Can I use titler to do this?

I don't have any knowledge about maps and I need help with this.

I'm trying to convert my image to a tiff image and submit it to /cog/tiles/{TileMatrixSetId}/{z}/{x}/{y}. {format} either PNG or TIFF always returns the error CRS is invalid: None.

[vincentsarago]

you first need to add geo location metadata to your data (e.g CRS and bounds to your file)

gdal_translate -of COG my.png my.tif -a_srs EPSG:4326 -a_ullr <ulx> <uly> <lrx> <lry>` 

if you just want to visualize your image (without geo localtion) you can maybe check https://github.com/developmentseed/titiler-image

[StringKe]

Thank you for your reply!

I'm trying to generate using the following command, the image displayed in cog/map overlay is black, how should I keep it in color.

gdal_translate -of GTiff -a_srs EPSG:4326 -a_ullr <ulx> <uly> <lrx> <lry> -co "ALPHA=YES" -co "COMPRESS=DEFLATE" -co "PREDICTOR=2" input.png output.tif

When I modify colormap_name these images will have some color change, what should I do if I want to keep the original color?

[StringKe]

Is bix some parameters affect, when I only have a few parameters url zoom these, the color is normal, thank you very much for the program.

[StringKe]

How can I generate all the images in advance and package them?

[vincentsarago]

When I modify colormap_name these images will have some color change, what should I do if I want to keep the original color?

@StringKe so I guess your input PNG is a palette png (mean with internal colormap).

Could you share the output of gdalinfo for both the png and the tif?

Is bix some parameters affect, when I only have a few parameters url zoom these, the color is normal, thank you very much for the program

I'm not sure I get that.

How can I generate all the images in advance and package them?

please checkout https://developmentseed.org/titiler/dynamic_tiling/ the idea of TiTiler is to not create tiles in advance. if you want that checkout gdal2xyz.py script and other static tile server