Merge four CMYK images into one RGB Image Java -

thanks in advance provide me, , sorry bad english.

i know there's lot of questions topic, have looked lot on internet (and stackoverflow too) haven't found answer this...

i have 4 images; each 1 of them in type_byte_gray color model. have loaded these 4 images using code:

int numelems = 4; bufferedimage[] img = new bufferedimage[numelems]; for(int i=0;i<numelems;i++){     fileinputstream in = new fileinputstream(args[i]);     img[i] = imageio.read(in);     in.close(); } 

just imageio read... need "merge" 4 images 1 rgb image... each 1 of images 1 channel cmyk image. these images have equal dimensions. have converted 4 images 1 cmyk image using code:

for(int j=0;j<img[0].getheight();j++){     //read current point color...     for(int k=0;k<numelems;k++){         colpunto[k] = (img[k].getrgb(i, j) & 0xff);     }      int colorpunto = convertcomponentsrgb(colpunto);      //now, set point...     out.setrgb(i, j, colorpunto);     } } 

this function "convertcomponentsrgb" natural math convert cmyk color rgb color...

function convertcomponentsrgb(int[] pointcolor){ float cyan = (float)pointcolor[0] / (float)255; float magenta = (float)pointcolor[1] / (float)255; float yellow = (float)pointcolor[2] / (float)255; float black = (float)pointcolor[3] / (float)255;  float c = min(1f,cyan * (1f - black) + black); //minimum value float m = min(1f,magenta * (1f - black) + black); //minimum value float y = min(1f, yellow * (1f - black) + black); //minimum value  result[0] = math.round(255f*(1f - c)); result[1] = math.round(255f*(1f - m)); result[2] = math.round(255f*(1f - y));      return (result[0]<<16) | (result[1]<<8) | result[2]; } 

the problem here is... speed. takes 12 seconds process 1 image, because we've read each pixel , write each pixel, , think "getrgb" , "setrgb" functions aren't quick (or, it's best way achieve this).

¿how can achieve this? have reading lot colormodel, filters, still don't understand how achieve in better time.

you can use getdata , setdata speed access pixels vs. getrgb , setrgb.

there's no need convert cmyk floating point , back, can work directly pixel values:

function convertcomponentsrgb(int[] pointcolor){     int r = max(0, 255 - (pointcolor[0] + pointcolor[3]));     int g = max(0, 255 - (pointcolor[1] + pointcolor[3]));     int b = max(0, 255 - (pointcolor[2] + pointcolor[3]));      return (r<<16) | (g<<8) | b; }