| /* |
| * jccolext.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1991-1996, Thomas G. Lane. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2009-2012, 2015, 2022, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * file. |
| * |
| * This file contains input colorspace conversion routines. |
| */ |
| |
| |
| /* This file is included by jccolor.c */ |
| |
| |
| /* |
| * Convert some rows of samples to the JPEG colorspace. |
| * |
| * Note that we change from the application's interleaved-pixel format |
| * to our internal noninterleaved, one-plane-per-component format. |
| * The input buffer is therefore three times as wide as the output buffer. |
| * |
| * A starting row offset is provided only for the output buffer. The caller |
| * can easily adjust the passed input_buf value to accommodate any row |
| * offset required on that side. |
| */ |
| |
| INLINE |
| LOCAL(void) |
| rgb_ycc_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf, |
| JSAMPIMAGE output_buf, JDIMENSION output_row, |
| int num_rows) |
| { |
| my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert; |
| register int r, g, b; |
| register JLONG *ctab = cconvert->rgb_ycc_tab; |
| register JSAMPROW inptr; |
| register JSAMPROW outptr0, outptr1, outptr2; |
| register JDIMENSION col; |
| JDIMENSION num_cols = cinfo->image_width; |
| |
| while (--num_rows >= 0) { |
| inptr = *input_buf++; |
| outptr0 = output_buf[0][output_row]; |
| outptr1 = output_buf[1][output_row]; |
| outptr2 = output_buf[2][output_row]; |
| output_row++; |
| for (col = 0; col < num_cols; col++) { |
| r = RANGE_LIMIT(inptr[RGB_RED]); |
| g = RANGE_LIMIT(inptr[RGB_GREEN]); |
| b = RANGE_LIMIT(inptr[RGB_BLUE]); |
| inptr += RGB_PIXELSIZE; |
| /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations |
| * must be too; we do not need an explicit range-limiting operation. |
| * Hence the value being shifted is never negative, and we don't |
| * need the general RIGHT_SHIFT macro. |
| */ |
| /* Y */ |
| outptr0[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] + |
| ctab[b + B_Y_OFF]) >> SCALEBITS); |
| /* Cb */ |
| outptr1[col] = (JSAMPLE)((ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] + |
| ctab[b + B_CB_OFF]) >> SCALEBITS); |
| /* Cr */ |
| outptr2[col] = (JSAMPLE)((ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] + |
| ctab[b + B_CR_OFF]) >> SCALEBITS); |
| } |
| } |
| } |
| |
| |
| /**************** Cases other than RGB -> YCbCr **************/ |
| |
| |
| /* |
| * Convert some rows of samples to the JPEG colorspace. |
| * This version handles RGB->grayscale conversion, which is the same |
| * as the RGB->Y portion of RGB->YCbCr. |
| * We assume rgb_ycc_start has been called (we only use the Y tables). |
| */ |
| |
| INLINE |
| LOCAL(void) |
| rgb_gray_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf, |
| JSAMPIMAGE output_buf, JDIMENSION output_row, |
| int num_rows) |
| { |
| my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert; |
| register int r, g, b; |
| register JLONG *ctab = cconvert->rgb_ycc_tab; |
| register JSAMPROW inptr; |
| register JSAMPROW outptr; |
| register JDIMENSION col; |
| JDIMENSION num_cols = cinfo->image_width; |
| |
| while (--num_rows >= 0) { |
| inptr = *input_buf++; |
| outptr = output_buf[0][output_row]; |
| output_row++; |
| for (col = 0; col < num_cols; col++) { |
| r = RANGE_LIMIT(inptr[RGB_RED]); |
| g = RANGE_LIMIT(inptr[RGB_GREEN]); |
| b = RANGE_LIMIT(inptr[RGB_BLUE]); |
| inptr += RGB_PIXELSIZE; |
| /* Y */ |
| outptr[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] + |
| ctab[b + B_Y_OFF]) >> SCALEBITS); |
| } |
| } |
| } |
| |
| |
| /* |
| * Convert some rows of samples to the JPEG colorspace. |
| * This version handles extended RGB->plain RGB conversion |
| */ |
| |
| INLINE |
| LOCAL(void) |
| rgb_rgb_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf, |
| JSAMPIMAGE output_buf, JDIMENSION output_row, |
| int num_rows) |
| { |
| register JSAMPROW inptr; |
| register JSAMPROW outptr0, outptr1, outptr2; |
| register JDIMENSION col; |
| JDIMENSION num_cols = cinfo->image_width; |
| |
| while (--num_rows >= 0) { |
| inptr = *input_buf++; |
| outptr0 = output_buf[0][output_row]; |
| outptr1 = output_buf[1][output_row]; |
| outptr2 = output_buf[2][output_row]; |
| output_row++; |
| for (col = 0; col < num_cols; col++) { |
| outptr0[col] = inptr[RGB_RED]; |
| outptr1[col] = inptr[RGB_GREEN]; |
| outptr2[col] = inptr[RGB_BLUE]; |
| inptr += RGB_PIXELSIZE; |
| } |
| } |
| } |