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Addition of variable JPEG2000 compression for different sizes #1

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Addition of variable JPEG2000 compression for different sizes #1

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0e8bfe9
Add .DS_Store to the .gitignore
rowanbeentje Dec 16, 2012
8437b65
Vary JPEG2000 compression levels by icon size for quality improvements
rowanbeentje Dec 16, 2012
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3 changes: 3 additions & 0 deletions .gitignore
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Original file line number Diff line number Diff line change
Expand Up @@ -13,3 +13,6 @@ build/*
xcuserdata
profile
*.moved-aside

# OS X Finder
.DS_Store
38 changes: 33 additions & 5 deletions oldiconutil/main.m
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,8 @@ int main(int argc, const char * argv[])
BOOL convertInPlace = NO;
BOOL listOnly = NO;
int nameArgumentPosition = 1;
NSNumber* jpegCompressionObj = [NSNumber numberWithFloat: 1.0];
float jpegCompressionLevel = 1.f;
NSNumber* jpegCompressionObj = [NSNumber numberWithFloat: jpegCompressionLevel];
NSBitmapImageFileType compressionType = NSJPEG2000FileType;
NSString* destCompression = @"jp2";

Expand Down Expand Up @@ -94,11 +95,10 @@ int main(int argc, const char * argv[])
}
}

// If a compression level has been specified, parse it from the remaining string and use it:
// If a compression level has been specified, parse it from the remaining string:
if( compStr.length > 0 )
{
float theCompression = [compStr floatValue];
jpegCompressionObj = [NSNumber numberWithFloat: theCompression];
jpegCompressionLevel = [compStr floatValue];
}
}

Expand Down Expand Up @@ -173,9 +173,37 @@ int main(int argc, const char * argv[])

if( shouldConvert )
{

// For JPEG2000, high compression levels work very well for large sizes,
// but cause very visible artefacts at smaller sizes. So if using JPEG2000
// output format, don't apply compression for small sizes; use the specified
// compression for the largest 1024*1024 (ic10) size, and use less compression
// for medium sizes.
float jpegCompressionForSize = jpegCompressionLevel;
if ( [destCompression isEqualToString:@"jp2"] ) {

// Use no compression for the smallest sizes (ic11: 16*16@2x; ic12: 32*32@2x, ic07: 128*128)
if ( strcmp(blockType, "ic11") == 0 || strcmp(blockType, "ic12") == 0 || strcmp(blockType, "ic07") == 0 ) {
jpegCompressionForSize = 1.f;

// For the 256*256 sizes, halve the compression level (ic08: 256*256; ic13: 128*128@2x)
} else if ( strcmp(blockType, "ic08") == 0 || strcmp(blockType, "ic13") == 0 ) {
jpegCompressionForSize = (jpegCompressionForSize + 1.f) / 2.f;

// For the 512*512 sizes, use three-quarter compression (ic09: 512*512, ic14: 256*256@2x)
} else if ( strcmp(blockType, "ic09") == 0 || strcmp(blockType, "ic14") == 0 ) {
jpegCompressionForSize = ((jpegCompressionForSize * 3) + 1.f) / 4.f;
}
}
jpegCompressionObj = [NSNumber numberWithFloat: jpegCompressionForSize];

if( !listOnly )
{
printf( "\tConverting PNG to %s\n", [destCompression UTF8String] );
if ( [destCompression isEqualToString:@"jp2"] || [destCompression isEqualToString:@"jpg"] ) {
printf( "\tConverting PNG to %s (JPEG compression %f)\n", [destCompression UTF8String], jpegCompressionForSize );
} else {
printf( "\tConverting PNG to %s\n", [destCompression UTF8String] );
}

NSBitmapImageRep * theImage = [[NSBitmapImageRep alloc] initWithData: currBlockData];
NSData * jp2Data = [theImage representationUsingType: NSJPEG2000FileType properties:
Expand Down