[Image-SIG] Result of testing convert

Edward C. Jones edcjones@erols.com
Wed, 25 Dec 2002 11:00:09 -0500


Conversions to mode "1" are often buggy because of problems with the
internal representation of mode "1". The expression
     Image.new("1", (1,1), 255).getpixel((0,0))
returns 255. I use Gentoo Linux 1.3 on a PC with gcc 2.95.3.

mode "1", value 0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "1", value 1 to mode
    "1"     1
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

--------------------------------

mode "L", value 0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "L", value 255 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

--------------------------------

mode "RGB", value (0, 0, 0) to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (255, 255, 255, 0)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "RGB", value (255, 255, 255) to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

--------------------------------

mode "RGBA", value (0, 0, 0, 0) to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 0)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (255, 255, 255, 0)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "RGBA", value (255, 255, 255, 255) to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

--------------------------------

mode "RGBX", value (0, 0, 0, 0) to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 0)
    "CMYK"  (255, 255, 255, 0)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "RGBX", value (255, 255, 255, 255) to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

--------------------------------

mode "CMYK", value (0, 0, 0, 0) to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     255
    "F"     255.0

mode "CMYK", value (255, 255, 255, 255) to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (255, 255, 255, 255)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

--------------------------------

mode "YCbCr", value (0, 0, 0, 0) to mode
    "1"     0
    "L"     0
    "RGB"   (0, 135, 0)
    "RGBA"  (0, 135, 0, 255)
    "RGBX"  (0, 135, 0, 255)
    "CMYK"  (255, 120, 255, 0)
    "YCbCr" (0, 0, 0)
    "I"     79
    "F"     79.2450027466

mode "YCbCr", value (255, 255, 255, 255) to mode
    "1"     255
    "L"     255
    "RGB"   (255, 120, 255)
    "RGBA"  (255, 120, 255, 255)
    "RGBX"  (255, 120, 255, 255)
    "CMYK"  (0, 135, 0, 0)
    "YCbCr" (255, 255, 255)
    "I"     175
    "F"     175.755004883

--------------------------------

mode "I", value -1024 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -1024
    "F"     -1024.0

mode "I", value -64 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -64
    "F"     -64.0

mode "I", value 0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "I", value 64 to mode
    "1"     0
    "L"     64
    "RGB"   (64, 64, 64)
    "RGBA"  (64, 64, 64, 255)
    "RGBX"  (64, 64, 64, 255)
    "CMYK"  (0, 0, 0, 191)
    "YCbCr" (64, 128, 128)
    "I"     64
    "F"     64.0

mode "I", value 1024 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     1024
    "F"     1024.0

--------------------------------

mode "F", value -1e+15 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -2147483648
    "F"     -9.99999986991e+14

mode "F", value -100000.0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -100000
    "F"     -100000.0

mode "F", value -1024.0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -1024
    "F"     -1024.0

mode "F", value -64.0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     -64
    "F"     -64.0

mode "F", value 0.0 to mode
    "1"     0
    "L"     0
    "RGB"   (0, 0, 0)
    "RGBA"  (0, 0, 0, 255)
    "RGBX"  (0, 0, 0, 255)
    "CMYK"  (0, 0, 0, 255)
    "YCbCr" (0, 128, 128)
    "I"     0
    "F"     0.0

mode "F", value 64.0 to mode
    "1"     0
    "L"     64
    "RGB"   (64, 64, 64)
    "RGBA"  (64, 64, 64, 255)
    "RGBX"  (64, 64, 64, 255)
    "CMYK"  (0, 0, 0, 191)
    "YCbCr" (64, 128, 128)
    "I"     64
    "F"     64.0

mode "F", value 1024.0 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     1024
    "F"     1024.0

mode "F", value 100000.0 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     100000
    "F"     100000.0

mode "F", value 1073741824.0 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     1073741824
    "F"     1073741824.0

mode "F", value 8589934592.0 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     -2147483648
    "F"     8589934592.0

mode "F", value 1e+15 to mode
    "1"     255
    "L"     255
    "RGB"   (255, 255, 255)
    "RGBA"  (255, 255, 255, 255)
    "RGBX"  (255, 255, 255, 255)
    "CMYK"  (0, 0, 0, 0)
    "YCbCr" (255, 128, 128)
    "I"     -2147483648
    "F"     9.99999986991e+14