Convert RGBA To RGB In Python


Answer :

You probably want to use an image's convert method:



import PIL.Image


rgba_image = PIL.Image.open(path_to_image)
rgb_image = rgba_image.convert('RGB')


In case of numpy array, I use this solution:



def rgba2rgb( rgba, background=(255,255,255) ):
    row, col, ch = rgba.shape

    if ch == 3:
        return rgba

    assert ch == 4, 'RGBA image has 4 channels.'

    rgb = np.zeros( (row, col, 3), dtype='float32' )
    r, g, b, a = rgba[:,:,0], rgba[:,:,1], rgba[:,:,2], rgba[:,:,3]

    a = np.asarray( a, dtype='float32' ) / 255.0

    R, G, B = background

    rgb[:,:,0] = r * a + (1.0 - a) * R
    rgb[:,:,1] = g * a + (1.0 - a) * G
    rgb[:,:,2] = b * a + (1.0 - a) * B

    return np.asarray( rgb, dtype='uint8' )


in which the argument rgba is a numpy array of type uint8 with 4 channels. The output is a numpy array with 3 channels of type uint8.



This array is easy to do I/O with library imageio using imread and imsave.



Comments

Post a Comment

Popular posts from this blog

Converting A String To Int In Groovy

Answer : Use the toInteger() method to convert a String to an Integer , e.g. int value = "99".toInteger() An alternative, which avoids using a deprecated method (see below) is int value = "66" as Integer If you need to check whether the String can be converted before performing the conversion, use String number = "66" if (number.isInteger()) { int value = number as Integer } Deprecation Update In recent versions of Groovy one of the toInteger() methods has been deprecated. The following is taken from org.codehaus.groovy.runtime.StringGroovyMethods in Groovy 2.4.4 /** * Parse a CharSequence into an Integer * * @param self a CharSequence * @return an Integer * @since 1.8.2 */ public static Integer toInteger(CharSequence self) { return Integer.valueOf(self.toString().trim()); } /** * @deprecated Use the CharSequence version * @see #toInteger(CharSequence) */ @Deprecated public static Integer toInteger(String self) { return toInteg...
Read more

"Cannot Create Cache Directory /home//.composer/cache/repo/https---packagist.org/, Or Directory Is Not Writable. Proceeding Without Cache"

Answer : if anyone pass through here, this is shorter solution: sudo chown -R $USER $HOME/.composer it seems to me the group information is missing in your command sudo chown -R <user> /home/<user>/.composer/cache/repo/https---packagist.org Shoud be sudo chown -R <user>:<group> /home/<user>/.composer/cache/repo/https---packagist.org But to avoid other permission issues, I would rather advise: sudo chown -R <user>:<group> /home/<user>/.composer/cache (you'll need access to other folders in there) and sudo chown <user>:<group> /home/<user>/.composer To make sure your user has permissions enough on the global composer folder. Mind the missing recursion so the user don't own keys created by root. If you need to find out the group: groups <user>
Read more

Android SDK Location Should Not Contain Whitespace, As This Cause Problems With NDK Tools

Answer : As the warning message states, the SDK location should not contain whitespace. Your SDK is at C:\Users\Giacomo B\AppData\Local\Android\sdk . There is a whitespace character in Giacomo B . The easiest solution is to move the SDK somewhere else, where there is no space or other whitespace character in the path, such as C:\Android\sdk . You can point both Android Studio installations to the new location. There is another way: Open up CMD ( as Administrator ) Type: mklink /J C:\Program-Files "C:\Program Files" ( Or in my case mklink /J C:\Program-Files-(x86) "C:\Program Files (x86)" ) Hit enter Magic happens! ( Check your C drive ) Now you can point to C:\Program-Files ( C:\Program-Files-(x86) ). just change the path: "c:\program files\android\sdk" to "c:\progra~1\android\sdk" or "c:\program files (x86)\android\sdk" to "c:\progra~2\android\sdk" note that the paths should not contain spaces.
Read more