matlabpnggrayscalebit-depth

Convert bitdepth of png image

How to convert the image with the following information: ColorType: truecolor Format: png bitDepth: 24

to a png grayscale image with bitdepth=8 in matlab ?

Solution

  • From the documentation for imwrite

    For color images, the BitDepth value is the number of bits per plane

    You ask matlab to write 3 colour channels with 8 bits each, which results in 24 bits. If you want grayscale, use rgb2gray first to convert to grayscale, then write.