# OSD text with black color showing black rectangles instead of characters

**URL:** <https://forum.amebaiot.com/t/osd-text-with-black-color-showing-black-rectangles-instead-of-characters/4516>\
**Category:** Multimedia\
**Tags:** rtl8735b\
**Created:** [November 12, 2025, 1:36pm UTC](https://forum.amebaiot.com/t/osd-text-with-black-color-showing-black-rectangles-instead-of-characters/4516 "2025-11-12T13:36:16Z")\
**Posts on this page:** 1\
**Showing post:** 10

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**Author:** ![yugandhar](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/yugandhar/32/2836_2.png) [@yugandhar](https://forum.amebaiot.com/u/yugandhar)\
**Post date:** [May 25, 2026, 1:28pm UTC](https://forum.amebaiot.com/t/osd-text-with-black-color-showing-black-rectangles-instead-of-characters/4516/10 "2026-05-25T13:28:19Z")

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Hi @Pammy ,

Thanks for the update. It is working now. Could you please update on below issues also.

> [@Ameba Pro2 Font & Bitmap Tool Link / Documentation](https://forum.amebaiot.com/t/ameba-pro2-font-bitmap-tool-link-documentation/4406/29):
>
> Hi @yugandhar, The clipping happens after the PNGs are converted into the ARGB4444 font table and rendered by the OSD module. Therefore, some fine tuning is needed during the PNG-to-ARGB4444 conversion process, especially for glyph alignment and positioning, which is done in the script that I have written. osd\_char\_w , osd\_char\_h that i have tested are, 28 56 32 64 64 128 Kindly try the attached header file, which was tuned based on the image you provided. Do let me know if there’s any iss…

> [@Text OSD with 31+ characters has issues](https://forum.amebaiot.com/t/text-osd-with-31-characters-has-issues/4852):
>
> Hi, For rts\_osd2\_type\_text when the string buffer has more than 31 characters, the trailing characters are not printing sometimes and total text ignored if more than 36+ characters are available. The OSD demo provided [ameba-rtos-pro2/component/video/osd2/isp\_osd\_example.c at main · Ameba-AIoT/ameba-rtos-pro2 · GitHub](https://github.com/Ameba-AIoT/ameba-rtos-pro2/blob/main/component/video/osd2/isp_osd_example.c) has string buffer of length 64, but it is not printing properly if we keep more than 31 characters. Please provide an update with fix for this issue and also [OSD text with black …](https://forum.amebaiot.com/t/osd-text-with-black-color-showing-black-rectangles-instead-of-characters/4516/8)

Thanks,

Yugandhar

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