lvgl/docs/libs/bmp.md

.. include:: /header.rst
:github_url: |github_link_base|/libs/bmp.md

BMP decoder

This extension allows the use of BMP images in LVGL. This implementation uses bmp-decoder library. The pixels are read on demand (not the whole image is loaded) so using BMP images requires very little RAM.

If enabled in lv_conf.h by LV_USE_BMP LVGL will register a new image decoder automatically so BMP files can be directly used as image sources. For example:

lv_img_set_src(my_img, "S:path/to/picture.bmp");

Note that, a file system driver needs to registered to open images from files. Read more about it here or just enable one in lv_conf.h with LV_USE_FS_...

Limitations

• Only BMP files are supported and BMP images as C array (lv_img_dsc_t) are not. It's because there is no practical differences between how the BMP files and LVGL's image format stores the image data.
• BMP files can be loaded only from file. If you want to store them in flash it's better to convert them to C array with LVGL's image converter.
• The BMP files color format needs to match with LV_COLOR_DEPTH. Use GIMP to save the image in the required format. Both RGB888 and ARGB888 works with LV_COLOR_DEPTH 32
• Palette is not supported.
• Because not the whole image is read in can not be zoomed or rotated.

Example

.. include:: ../../examples/libs/bmp/index.rst

API

.. doxygenfile:: lv_bmp.h
  :project: lvgl