Suggestion: ImageCopyResizedBicubic

Here's the code for my ImageCopyResizedBicubic function, a function that implements bicubic interpolation within the image scale function. --------------------------------------------------------------------------cut-------------------------------------------------------------------------- /* {{{ proto int imagecopyresizedbicubic(int dst_im, int src_im, int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h) Copy and resize part of an image */ PHP_FUNCTION(imagecopyresizedbicubic) { zval **SIM, **DIM, **SX, **SY, **SW, **SH, **DX, **DY, **DW, **DH; gdImagePtr im_dst, im_src; int srcH, srcW, dstH, dstW, srcY, srcX, dstY, dstX; int i, j; int r, g, b, c1,c2,c3,c4,color; float sX, sY; float scaleX,scaleY,scaleX2,scaleY2; GDLS_FETCH(); if (ZEND_NUM_ARGS() != 10 || zend_get_parameters_ex(10, &DIM, &SIM, &DX, &DY, &SX, &SY, &DW, &DH, &SW, &SH) == FAILURE) { WRONG_PARAM_COUNT; } ZEND_FETCH_RESOURCE(im_dst, gdImagePtr, DIM, -1, "Image", le_gd); ZEND_FETCH_RESOURCE(im_src, gdImagePtr, SIM, -1, "Image", le_gd); convert_to_long_ex(SX); convert_to_long_ex(SY); convert_to_long_ex(SW); convert_to_long_ex(SH); convert_to_long_ex(DX); convert_to_long_ex(DY); convert_to_long_ex(DW); convert_to_long_ex(DH); srcX = Z_LVAL_PP(SX); srcY = Z_LVAL_PP(SY); srcH = Z_LVAL_PP(SH); srcW = Z_LVAL_PP(SW); dstX = Z_LVAL_PP(DX); dstY = Z_LVAL_PP(DY); dstH = Z_LVAL_PP(DH); dstW = Z_LVAL_PP(DW); // copy the palette (this is a bug since it doesnt seem to be possible to make a truecolor bitmap as output, so we just have to use the old palette) for( i=0; i<256; i++ ) { gdImageColorAllocate( im_dst, im_src->red[i], im_src->green[i], im_src->blue[i] ); }; // gdImageCopyResized(im_dst, im_src, dstX, dstY, srcX, srcY, dstW, dstH, srcW, srcH); scaleX = (float)(srcW-1) / (float)dstW; scaleY = (float)(srcH-1) / (float)dstH; scaleX2 = scaleX/2.0f; scaleY2 = scaleY/2.0f; for( j=0; j<dstH; j++ ) { for( i=0; i<dstW; i++ ) { sX = (float)i * scaleX; sY = (float)j * scaleY; c1 = gdImageGetPixel(im_src, (int)(sX), (int)(sY+scaleY2) ); c2 = gdImageGetPixel(im_src, (int)(sX), (int)(sY) ); c3 = gdImageGetPixel(im_src, (int)(sX+scaleX2), (int)(sY+scaleY2) ); c4 = gdImageGetPixel(im_src, (int)(sX+scaleX2), (int)(sY) ); r = (im_src->red[c1] + im_src->red[c2] + im_src->red[c3] + im_src->red[c4]) / 4; g = (im_src->green[c1] + im_src->green[c2] + im_src->green[c3] + im_src->green[c4]) / 4; b = (im_src->blue[c1] + im_src->blue[c2] + im_src->blue[c3] + im_src->blue[c4]) / 4; color=gdImageColorClosest(im_dst,r,g,b); gdImageSetPixel( im_dst, (i+dstX),(j+dstY), color ); }; }; RETURN_TRUE; } --------------------------------------------------------------------------cut-------------------------------------------------------------------------- good result when scaling down images, result wont be good when scaling up a image since the palette is copied from the source-bitmap so, if the source bitmap is 4colors the resulting bitmap is also 4color :/ i dont know if it is possible to create a image with more than 256 colors in the gd lib since i didnt have the source ... but, hey, this works for scaling down images... i'll try to fix the downscaling bug when i know how to allocate more than 256 colors... if anyone know how to do that, please contact me!