Sorry for the false alarm.
However, it is odd that this only happens when I run the script using mpc and it does not happen with miff: or png.
_____________________________________________
IM 6.4.8-1 Q16 Mac OSX Tiger
I was given a high resolution (3kx2k) image from a digital camera which I then resized to the following:
P1040409c.jpg

I then processed it with my saturation script, the core of which is the following using no change in saturation (value=1).
dir="."
tmpA="$dir/saturation_$$.mpc"
tmpB="$dir/saturation_$$.cache"
tmp0="$dir/saturation_0_$$.png"
tmp1="$dir/saturation_1_$$.png"
tmp2="$dir/saturation_2_$$.png"
infile="P1040409c.jpg"
outfile="P1040409c_sat1.jpg"
value=1.0
if convert -quiet -regard-warnings "$infile" +repage "$tmpA"
then
convert $tmpA -colorspace HSL -channel R -separate $tmp0
convert $tmpA -colorspace HSL -channel G -separate $tmp1
convert $tmpA -colorspace HSL -channel B -separate $tmp2
convert $tmp0 -colorspace HSL \
$tmp0 -compose CopyRed -composite \
\( $tmp1 -evaluate multiply $value \) -compose CopyGreen -composite \
$tmp2 -compose CopyBlue -composite \
-colorspace RGB $outfile
else
errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE ---"
fi
The result P1040409c_sat1.jpg looks as follows, scrunched vertically.

If I add -strip to remove the EXIF data. The result looks normal. Also if I use .miff or .png for $tmpA, the result looks normal even without the -strip. tmp0, tmp1 and tmp2 look fine, so it appears to be happening at the last composite stage before the -colorspace RGB $outfile (as I inserted a -write there and that file was scrunched).
Is this supposed to happen? If so, what line in the EXIF data is causing this.
identify -verbose P1040409c.jpg
Image: P1040409c.jpg
Format: JPEG (Joint Photographic Experts Group JFIF format)
Class: DirectClass
Geometry: 512x384+0+0
Resolution: 72x72
Print size: 7.11111x5.33333
Units: PixelsPerInch
Type: TrueColor
Endianess: Undefined
Colorspace: RGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
red:
min: 3 (0.0117647)
max: 252 (0.988235)
mean: 138.127 (0.541676)
standard deviation: 34.3348 (0.134646)
green:
min: 5 (0.0196078)
max: 251 (0.984314)
mean: 131.545 (0.515864)
standard deviation: 35.767 (0.140263)
blue:
min: 4 (0.0156863)
max: 255 (1)
mean: 127.705 (0.500804)
standard deviation: 40.9372 (0.160538)
Rendering intent: Undefined
Interlace: None
Background color: white
Border color: rgb(223,223,223)
Matte color: grey74
Transparent color: black
Page geometry: 512x384+0+0
Dispose: Undefined
Iterations: 0
Compression: JPEG
Quality: 92
Orientation: TopLeft
Properties:
create-date: 2008-12-25T22:08:39+00:00
exif:ColorSpace: 1
exif:ComponentsConfiguration: 1, 2, 3, 0
exif:CompressedBitsPerPixel: 4/1
exif:Compression: 6
exif:Contrast: 0
exif:CustomRendered: 0
exif:DateTime: 2008:12:06 19:26:53
exif:DateTimeDigitized: 2008:12:06 19:26:53
exif:DateTimeOriginal: 2008:12:06 19:26:53
exif:DigitalZoomRatio: 0/10
exif:ExifImageLength: 2448
exif:ExifImageWidth: 3264
exif:ExifOffset: 420
exif:ExifVersion: 48, 50, 50, 48
exif:ExposureBiasValue: 0/100
exif:ExposureMode: 0
exif:ExposureProgram: 2
exif:ExposureTime: 10/300
exif:FileSource: 3
exif:Flash: 9
exif:FlashPixVersion: 48, 49, 48, 48
exif:FNumber: 36/10
exif:FocalLength: 264/10
exif:FocalLengthIn35mmFilm: 125
exif:GainControl: 1
exif:InteroperabilityIndex: R98
exif:InteroperabilityOffset: 6652
exif:InteroperabilityVersion: 48, 49, 48, 48
exif:ISOSpeedRatings: 125
exif:JPEGInterchangeFormat: 6804
exif:JPEGInterchangeFormatLength: 5315
exif:LightSource: 4
exif:Make: Panasonic
exif:MakerNote: 80, 97, 110, 97, 115, 111, 110, 105, 99, 0, 0, 0, 30, 0, 1, 0, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 2, 0, 7, 0, 4, 0, 0, 0, 0, 1, 0, 19, 3, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 7, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 15, 0, 1, 0, 2, 0, 0, 0, 16, 0, 0, 0, 26, 0, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 28, 0, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 31, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 32, 0, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 33, 0, 7, 0, 192, 20, 0, 0, 16, 5, 0, 0, 34, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 35, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 36, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 37, 0, 7, 0, 16, 0, 0, 0, 208, 25, 0, 0, 38, 0, 7, 0, 4, 0, 0, 0, 48, 49, 48, 52, 39, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 40, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 41, 0, 4, 0, 1, 0, 0, 0, 239, 1, 0, 0, 42, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 43, 0, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 44, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 45, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 46, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 47, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 48, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 49, 0, 3, 0, 1, 0, 0, 0, 2, 0, 0, 0, 50, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0, 51, 0, 2, 0, 20, 0, 0, 0, 224, 25, 0, 0, 52, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 53, 0, 3, 0, 1, 0, 0, 0, 1, 0, 0, 0, 68, 86, 1, 2, 69, 80, 0, 0, 240, 63, 68, 66, 224, 3, 240, 63, 65, 70, 178, 0, 96, 71, 32, 128, 98, 71, 17, 1, 100, 71, 48, 0, 102, 71, 0, 0, 78, 71, 44, 0, 114, 71, 1, 0, 116, 71, 0, 0, 122, 71, 0, 0, 124, 71, 252, 255, 126, 71, 0, 0, 64, 71, 121, 7, 66, 71, 22, 23, 76, 71, 34, 22, 240, 71, 4, 22, 242, 71, 64, 22, 92, 71, 45, 1, 118, 71, 96, 0, 120, 71, 0, 0, 82, 71, 248, 1, 86, 71, 35, 0, 84, 71, 132, 0, 108, 71, 127, 4, 112, 71, 192, 0, 110, 71, 10, 2, 88, 71, 156, 0, 158, 71, 106, 0, 156, 71, 36, 4, 140, 71, 0, 0, 142, 71, 1, 0, 138, 71, 22, 23, 144, 71, 1, 0, 146, 71, 1, 0, 148, 71, 0, 0, 150, 71, 0, 0, 152, 71, 4, 2, 154, 71, 1, 2, 222, 70, 3, 81, 238, 71, 0, 0, 90, 71, 0, 0, 138, 89, 0, 0, 140, 89, 0, 0, 4, 70, 4, 2, 10, 70, 22, 23, 240, 63, 83, 84, 74, 0, 164, 70, 175, 3, 166, 70, 108, 5, 168, 70, 189, 1, 170, 70, 0, 144, 172, 70, 26, 4, 250, 71, 95, 5, 174, 70, 1, 0, 176, 70, 62, 0, 182, 70, 206, 1, 184, 70, 157, 2, 186, 70, 6, 93, 244, 71, 0, 0, 246, 71, 0, 0, 178, 70, 136, 2, 180, 70, 3, 0, 176, 68, 0, 0, 178, 68, 0, 0, 240, 63, 65, 69, 214, 0, 60, 69, 32, 0, 20, 69, 57, 1, 234, 70, 57, 1, 236, 70, 53, 1, 40, 69, 57, 1, 44, 69, 119, 1, 36, 69, 198, 3, 16, 69, 149, 2, 18, 69, 130, 2, 32, 69, 132, 1, 54, 69, 92, 1, 34, 69, 96, 1, 58, 69, 1, 0, 232, 71, 1, 0, 59, 69, 1, 0, 233, 71, 0, 0, 38, 69, 125, 0, 42, 69, 55, 0, 192, 70, 0, 0, 194, 70, 0, 0, 200, 89, 128, 2, 198, 89, 197, 1, 82, 69, 85, 2, 80, 69, 197, 1, 67, 69, 0, 0, 62, 69, 1, 0, 28, 69, 142, 0, 68, 69, 179, 0, 34, 74, 52, 1, 192, 89, 1, 0, 193, 89, 0, 0, 232, 70, 6, 45, 204, 70, 0, 0, 212, 70, 0, 1, 206, 70, 0, 0, 208, 70, 0, 0, 214, 70, 0, 0, 80, 88, 0, 0, 218, 70, 0, 0, 197, 89, 1, 0, 74, 69, 1, 0, 76, 69, 1, 0, 78, 69, 1, 0, 239, 70, 1, 0, 212, 89, 0, 0, 214, 89, 155, 28, 216, 89, 240, 31, 218, 89, 23, 13, 220, 89, 5, 0, 238, 70, 0, 0, 236, 89, 0, 0, 234, 71, 0, 0, 240, 63, 87, 66, 14, 1, 0, 68, 183, 1, 2, 68, 170, 1, 92, 68, 17, 1, 4, 68, 38, 1, 6, 68, 248, 0, 18, 69, 130, 2, 26, 68, 106, 0, 94, 68, 148, 0, 95, 68, 8, 0, 18, 68, 37, 1, 20, 68, 247, 0, 22, 68, 109, 1, 24, 68, 25, 1, 204, 68, 14, 1, 206, 68, 50, 2, 208, 68, 126, 1, 210, 68, 84, 1, 220, 68, 201, 1, 222, 68, 70, 1, 180, 68, 0, 0, 182, 68, 0, 0, 48, 68, 96, 0, 56, 68, 126, 0, 50, 68, 100, 0, 58, 68, 117, 0, 52, 68, 240, 255, 60, 68, 24, 0, 54, 68, 42, 0, 62, 68, 112, 0, 76, 68, 12, 1, 78, 68, 238, 0, 192, 68, 38, 1, 194, 68, 248, 0, 234, 68, 0, 0, 128, 69, 148, 0, 130, 69, 134, 0, 131, 69, 119, 0, 132, 69, 0, 0, 134, 69, 0, 0, 135, 69, 0, 0, 136, 69, 0, 0, 138, 69, 0, 0, 139, 69, 0, 0, 140, 69, 0, 0, 142, 69, 155, 0, 143, 69, 126, 0, 144, 69, 0, 0, 146, 69, 0, 0, 147, 69, 0, 0, 82, 68, 169, 0, 84, 68, 166, 0, 86, 68, 169, 0, 88, 68, 166, 0, 212, 68, 20, 1, 214, 68, 253, 0, 216, 68, 0, 1, 218, 68, 250, 0, 212, 93, 0, 0, 240, 68, 0, 0, 242, 68, 0, 0, 244, 68, 0, 0, 246, 68, 0, 0, 248, 68, 0, 0, 250, 68, 0, 0, 252, 68, 0, 0, 254
exif:MaxApertureValue: 30/10
exif:MeteringMode: 5
exif:Model: DMC-FZ30
exif:Orientation: 1
exif:PrintImageMatching: 80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 14, 0, 1, 0, 22, 0, 22, 0, 2, 0, 0, 0, 0, 0, 3, 0, 100, 0, 0, 0, 7, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 11, 0, 172, 0, 0, 0, 12, 0, 0, 0, 0, 0, 13, 0, 0, 0, 0, 0, 14, 0, 196, 0, 0, 0, 0, 1, 5, 0, 0, 0, 1, 1, 1, 0, 0, 0, 16, 1, 128, 0, 0, 0, 9, 17, 0, 0, 16, 39, 0, 0, 11, 15, 0, 0, 16, 39, 0, 0, 151, 5, 0, 0, 16, 39, 0, 0, 176, 8, 0, 0, 16, 39, 0, 0, 1, 28, 0, 0, 16, 39, 0, 0, 94, 2, 0, 0, 16, 39, 0, 0, 139, 0, 0, 0, 16, 39, 0, 0, 203, 3, 0, 0, 16, 39, 0, 0, 229, 27, 0, 0, 16, 39, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
exif:ResolutionUnit: 2
exif:Saturation: 0
exif:SceneCaptureType: 0
exif:SceneType: 1
exif:SensingMethod: 2
exif:Sharpness: 0
exif:Software: Ver.1.0
exif:WhiteBalance: 0
exif:YCbCrPositioning: 2
exif:YResolution: 72/1
jpeg:colorspace: 2
jpeg:sampling-factor: 2x1,1x1,1x1
modify-date: 2008-12-25T19:44:27+00:00
signature: 4cf38f057b508e3adb0c77c3efda3cd480a93092471084a8e6304cec33992a6d
Profiles:
Profile-exif: 27292 bytes
Artifacts:
verbose: true
Tainted: False
Filesize: 73.6kb
Number pixels: 192kb
Version: ImageMagick 6.4.8 2008-12-24 Q16 http://www.imagemagick.org