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tjGetScaledSize() would never be able to accommodate scaling factors > 1, so replace it with a function that returns a list of fractional scaling factors that TurboJPEG supports.

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This commit is contained in:
DRC
2011-03-01 09:53:07 +00:00
parent da6a1f6c76
commit be085e08b3
12 changed files with 269 additions and 262 deletions
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36
java/org/libjpegturbo/turbojpeg/TJDecompressor.java
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@@ -76,8 +76,19 @@ public class TJDecompressor {
throw new Exception("JPEG buffer not initialized");
if(desiredWidth < 0 || desiredHeight < 0)
throw new Exception("Invalid argument in getScaledWidth()");
return getScaledWidth(jpegWidth, jpegHeight, desiredWidth,
desiredHeight);
TJ.ScalingFactor sf [] = TJ.getScalingFactors();
if(desiredWidth == 0) desiredWidth = jpegWidth;
if(desiredHeight == 0) desiredHeight = jpegHeight;
int scaledWidth = jpegWidth, scaledHeight = jpegHeight;
for(int i=0; i<sf.length; i++) {
scaledWidth = (jpegWidth * sf[i].num + sf[i].denom - 1) / sf[i].denom;
scaledHeight = (jpegHeight * sf[i].num + sf[i].denom - 1) / sf[i].denom;
if(scaledWidth <= desiredWidth && scaledHeight <= desiredHeight)
break;
}
if(scaledWidth > desiredWidth || scaledHeight > desiredHeight)
throw new Exception("Could not scale down to desired image dimensions");
return scaledWidth;
}
public int getScaledHeight(int desiredWidth, int desiredHeight)
@@ -86,8 +97,19 @@ public class TJDecompressor {
throw new Exception("JPEG buffer not initialized");
if(desiredWidth < 0 || desiredHeight < 0)
throw new Exception("Invalid argument in getScaledHeight()");
return getScaledHeight(jpegWidth, jpegHeight, desiredWidth,
desiredHeight);
TJ.ScalingFactor sf [] = TJ.getScalingFactors();
if(desiredWidth == 0) desiredWidth = jpegWidth;
if(desiredHeight == 0) desiredHeight = jpegHeight;
int scaledWidth = jpegWidth, scaledHeight = jpegHeight;
for(int i=0; i<sf.length; i++) {
scaledWidth = (jpegWidth * sf[i].num + sf[i].denom - 1) / sf[i].denom;
scaledHeight = (jpegHeight * sf[i].num + sf[i].denom - 1) / sf[i].denom;
if(scaledWidth <= desiredWidth && scaledHeight <= desiredHeight)
break;
}
if(scaledWidth > desiredWidth || scaledHeight > desiredHeight)
throw new Exception("Could not scale down to desired image dimensions");
return scaledHeight;
}
public void decompress(byte [] dstBuf, int desiredWidth, int pitch,
@@ -224,12 +246,6 @@ public class TJDecompressor {
int flags)
throws Exception;
private native int getScaledWidth(int jpegWidth, int jpegHeight,
int desiredWidth, int desiredHeight) throws Exception;
private native int getScaledHeight(int jpegWidth, int jpegHeight,
int desiredWidth, int desiredHeight) throws Exception;
static {
System.loadLibrary("turbojpeg");
}