Tesseract Errors and Missing PNG Library

[Fabelwesen]

First of all, I want to thank you very much; your OCR tools are exactly what I was looking for! :) Keep up the great work!

When I load and use this plugin in OBS, I get some errors that I believe are related to Tesseract. Can these be ignored?

info: [obs-ocr] Loading tesseract model from: /usr/share/obs/obs-plugins/obs-ocr/tessdata
Error in pixReadMemTiff: function not present
Error in pixReadMem: tiff: no pix returned
Error in pixaGenerateFontFromString: pix not made
Error in bmfCreate: font pixa not made
info: [obs-ocr] Starting Tesseract thread, update timer: 100
info: Switched to scene 'Szene'
info: ------------------------------------------------
info: Loaded scenes:
info: - scene 'Szene':
info: - source: 'FLIR' (xshm_input)
info: - filter: 'Schärfung' (sharpness_filter_v2)
info: - filter: 'OCR-Filter' (ocr_filter)
info: - filter: 'Farbkorrektur' (color_filter_v2)
info: ------------------------------------------------
Warning in changeFormatForMissingLib: png library missing; output bmp format
Warning in changeFormatForMissingLib: png library missing; output bmp format
Warning in changeFormatForMissingLib: png library missing; output bmp format
Warning in changeFormatForMissingLib: png library missing; output bmp format