Looking for a way to speed up png file writing

[kmsterrett]

Hello,

I have a pixel array that contains RGB data.
This code correctly creates that png file, but it take a long time.
About 700ms.
Does anyone know of a way for me to speed this up?
I will need to write as many of 50-60 files, so I do not want my user
to wait.
Thanks in advance for any advice.
Kim
-----this is the code

WritableRaster wr;
DataBuffer db = new DataBufferUShort(pixels,720*504);
BandedSampleModel sm = new BandedSampleModel
(DataBuffer.TYPE_USHORT,720,504,3);
wr = Raster.createWritableRaster(sm,db,new Point(0,0));
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
ColorModel cm = new ComponentColorModel(cs,false,
false,Transparency.OPAQUE,DataBuffer.TYPE_USHORT);

final BufferedImage bi = new BufferedImage(cm, wr, false, null);
RenderedImage renImage = (RenderedImage)bi;

//Write generated image to a file
try {
// Save as PNG
if (renImage != null){
File filImg2d = new File(fileName + ".png");
ImageIO.write(renImage, "png", filImg2d);
}
}
catch (Exception e){
System.out.println("Error in writing image to file " +
e.getMessage() + " );
}

 

[Andrew Thompson]

Does anyone know of a way for me to speed this up?

Post an SSCCE?

I will need to write as many of 50-60 files ..

Where is the loop in your code?

Andrew T.

 

[kmsterrett]

The loop for multiple files is in another method, that calls this
WriteToFile with the filename string.

The pixels array is 2d array class variable,
short [][] pixels = new short [3][720*504];

 

[Andrew Thompson]

The loop ..

What loop?

..for multiple files is in another method, that calls this
WriteToFile with the filename string.

The pixels array is 2d array class variable,
short [][] pixels = new short [3][720*504];

...good. Now getting back to what I actually
suggested.

<http://www.physci.org/codes/sscce.html>

The processing can be sped up by moving the
try/catch, as well as possibly some variable
declaration/initialisation, outside the loop.
But for the best answer, post an SSCCE
(as opposed to code snippets and descriptions).

Andrew T.

 

[Knute Johnson]

Hello,

I have a pixel array that contains RGB data.
This code correctly creates that png file, but it take a long time.
About 700ms.
Does anyone know of a way for me to speed this up?
I will need to write as many of 50-60 files, so I do not want my user
to wait.
Thanks in advance for any advice.
Kim
-----this is the code

WritableRaster wr;
DataBuffer db = new DataBufferUShort(pixels,720*504);
BandedSampleModel sm = new BandedSampleModel
(DataBuffer.TYPE_USHORT,720,504,3);
wr = Raster.createWritableRaster(sm,db,new Point(0,0));
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
ColorModel cm = new ComponentColorModel(cs,false,
false,Transparency.OPAQUE,DataBuffer.TYPE_USHORT);

final BufferedImage bi = new BufferedImage(cm, wr, false, null);
RenderedImage renImage = (RenderedImage)bi;

//Write generated image to a file
try {
// Save as PNG
if (renImage != null){
File filImg2d = new File(fileName + ".png");
ImageIO.write(renImage, "png", filImg2d);
}
}
catch (Exception e){
System.out.println("Error in writing image to file " +
e.getMessage() + " );
}

You could buffer the output stream. Do you actually need to write
faster or just make it appear to the user that it went quickly?