# PyGMT fig.tilemap() error: grdimage \[ERROR\]: Byte image without indexed color requires a CPT via -C

**URL:** <https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387>\
**Category:** PyGMT Q&A\
**Created:** [October 28, 2023, 1:15pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387 "2023-10-28T13:15:29Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![mkononets](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/mkononets/32/4029_2.png) [@mkononets](https://forum.generic-mapping-tools.org/u/mkononets)\
**Post date:** [October 28, 2023, 1:15pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387/1 "2023-10-28T13:15:29Z")

</div>

script to reproduce:

```auto
import pygmt
fig = pygmt.Figure()
fig.tilemap(
    #region=[-63.6833, -63.5667, 44.65, 44.7333],
    region=[-7088268.57626, -7078991.95203, 5567892.48683, 5579637.51917],
    #projection="EPSG:3857",
    lonlat=False,
    projection="x1:50000",
    # Set level of details (0-22)
    # Please note, not all zoom levels are always available
    zoom=14,
    # Use tiles from OpenStreetMap tile server
    source="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
)
fig.savefig("tilemap_EPSG3857.png")

```

error messages:

```auto
Traceback (most recent call last):
  File "/home/mkononets/GIS data/Bedford Basin/test_pygmt_tilemap_BB.py", line 3, in <module>
    fig.tilemap(
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/helpers/decorators.py", line 598, in new_module
    return module_func(*args, **kwargs)
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/helpers/decorators.py", line 738, in new_module
    return module_func(*args, **kwargs)
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/src/tilemap.py", line 148, in tilemap
    lib.call_module(
  File "/home/mkononets/mambaforge/envs/pygmt/lib/python3.11/site-packages/pygmt/clib/session.py", line 628, in call_module
    raise GMTCLibError(
pygmt.exceptions.GMTCLibError: Module 'grdimage' failed with status code 79:
grdimage [ERROR]: Byte image without indexed color requires a CPT via -C

```

`pygmt.show_versions()`:

```auto
PyGMT information:
  version: v0.10.0
System information:
  python: 3.11.4 | packaged by conda-forge | (main, Jun 10 2023, 18:08:17) [GCC 12.2.0]
  executable: /home/mkononets/mambaforge/envs/pygmt/bin/python3.11
  machine: Linux-5.15.0-53-generic-x86_64-with-glibc2.35
Dependency information:
  numpy: 1.25.2
  pandas: 2.0.3
  xarray: 2023.7.0
  netCDF4: 1.6.4
  packaging: 23.1
  contextily: 1.3.0
  geopandas: 0.13.2
  IPython: 8.14.0
  rioxarray: 0.14.1
  ghostscript: 10.02.0
GMT library information:
  binary version: 6.5.0_5496e05_2023.10.05
  cores: 4
  grid layout: rows
  image layout: 
  library path: /home/mkononets/mambaforge/envs/pygmt/lib/libgmt.so
  padding: 2
  plugin dir: /home/mkononets/mambaforge/envs/pygmt/lib/gmt/plugins
  share dir: /home/mkononets/mambaforge/envs/pygmt/share/gmt
  version: 6.5.0

```

---

<div class="post-metadata">

**Author:** ![pwessel](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/pwessel/32/30_2.png) [@pwessel](https://forum.generic-mapping-tools.org/u/pwessel)\
**Post date:** [October 28, 2023, 1:36pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387/2 "2023-10-28T13:36:53Z")

</div>

Hm, recent changes related to grdimage which might be after your Oct 5 master. If you can, update gmt master and let us know if the same error

---

<div class="post-metadata">

**Author:** ![mkononets](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/mkononets/32/4029_2.png) [@mkononets](https://forum.generic-mapping-tools.org/u/mkononets)\
**Post date:** [October 28, 2023, 1:53pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387/3 "2023-10-28T13:53:09Z")

</div>

> [@pwessel](#):
>
> recent changes related to grdimage which might be after your Oct 5 master. If you can, update gmt master and let us know if the same error

Thanks! I will certainly update and test, once the updated gmt 6.5.0 `conda` packages are available.

---

<div class="post-metadata">

**Author:** ![mkononets](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/mkononets/32/4029_2.png) [@mkononets](https://forum.generic-mapping-tools.org/u/mkononets)\
**Post date:** [October 29, 2023, 12:25pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387/4 "2023-10-29T12:25:25Z")

</div>

downgrade to gmt 6.4.0 solved this issue, tilemap is generated as expected.

---

<div class="post-metadata">

**Author:** ![mkononets](https://yyz1.discourse-cdn.com/flex047/user_avatar/forum.generic-mapping-tools.org/mkononets/32/4029_2.png) [@mkononets](https://forum.generic-mapping-tools.org/u/mkononets)\
**Post date:** [January 2, 2024, 11:25pm UTC](https://forum.generic-mapping-tools.org/t/pygmt-fig-tilemap-error-grdimage-error-byte-image-without-indexed-color-requires-a-cpt-via-c/4387/5 "2024-01-02T23:25:15Z")

</div>

there’s finally `gmt-6.5.0.dev9+0776994-h5cae338_1.conda` available, with this build the issue seems gone for good

```auto
PyGMT information:
  version: v0.10.0
System information:
  python: 3.11.4 | packaged by conda-forge | (main, Jun 10 2023, 18:08:17) [GCC 12.2.0]
  executable: /home/mkononets/mambaforge/envs/pygmt/bin/python3.11
  machine: Linux-5.15.0-53-generic-x86_64-with-glibc2.35
Dependency information:
  numpy: 1.25.2
  pandas: 2.0.3
  xarray: 2023.7.0
  netCDF4: 1.6.5
  packaging: 23.1
  contextily: 1.3.0
  geopandas: 0.13.2
  IPython: 8.14.0
  rioxarray: 0.14.1
  ghostscript: 10.02.1
GMT library information:
  binary version: 6.5.0
  cores: 4
  grid layout: rows
  image layout: 
  library path: /home/mkononets/mambaforge/envs/pygmt/lib/libgmt.so
  padding: 2
  plugin dir: /home/mkononets/mambaforge/envs/pygmt/lib/gmt/plugins
  share dir: /home/mkononets/mambaforge/envs/pygmt/share/gmt
  version: 6.5.0

```