IG_DIB_pix

This function gets a pixel from the specified location in the image.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_DIB_pix_get( HIGEAR hIGear, AT_PIXPOS xpos, AT_PIXPOS ypos, HIGPIXEL* lphPixel );

Arguments:

Name	Type	Description
hIGear	HIGEAR	HIGEAR handle of image from which to get pixel.
xpos	AT_PIXPOS	X coordinate (0 to width-1).
ypos	AT_PIXPOS	Y coordinate (0 to height-1).
lphPixel	HIGPIXEL*	Returns object containing pixel data.

Return Value:

Returns the number of ImageGear errors that occurred during this function call. If there are no errors, the return value is IGE_SUCCESS.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++.

Sample:

Pixel Access

Example:

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AT_ERRCOUNT nErrcount; /* Number of errors on stack / HIGEAR hImage; / Handle of image / HIGPIXEL hPix; / Handle of pixel / AT_DIMENSION w, h; / Width and height of image / AT_INT nChannels; / Number of channels in image / AT_DIMENSION x, y; / Used to loop over image / AT_INT c; / Used to loop over channels / AT_INT nDepth; / Channel depth / AT_UINT inverted; / Inverted channel value / / Invert colors in upper-left quadrant of image */ nErrcount = IG_load_file("test.jpg", &hImage); nErrcount = IG_image_channel_count_get(hImage, &nChannels); nErrcount = IG_image_dimensions_get(hImage, &w, &h, NULL); for (y = 0; y < h / 2; y++) for (x = 0; x < w / 2; x++) { nErrcount = IG_DIB_pix_get(hImage, x, y, &hPix); for (c = 0; c < nChannels; c++) { IG_image_channel_depth_get(hImage, c, &nDepth); nDepth = (1 << nDepth) - 1; inverted = nDepth - IG_pixel_value_get(hPix, c); IG_pixel_value_set(hPix, c, inverted); } nErrcount = IG_DIB_pix_set(hImage, x, y, hPix); IG_pixel_delete(hPix); } nErrcount = IG_save_file(hImage, "test.bmp", IG_SAVE_BMP_UNCOMP); IG_image_delete(hImage);

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AT_ERRCOUNT nErrcount;  /* Number of errors on stack */
HIGEAR hImage;          /* Handle of image */
HIGPIXEL hPix;          /* Handle of pixel */
AT_DIMENSION w, h;      /* Width and height of image */
AT_INT nChannels;       /* Number of channels in image */
AT_DIMENSION x, y;      /* Used to loop over image */
AT_INT c;               /* Used to loop over channels */
AT_INT nDepth;          /* Channel depth */
AT_UINT inverted;       /* Inverted channel value */
/* Invert colors in upper-left quadrant of image */
nErrcount = IG_load_file("test.jpg", &hImage);
nErrcount = IG_image_channel_count_get(hImage, &nChannels);
nErrcount = IG_image_dimensions_get(hImage, &w, &h, NULL);
for (y = 0; y < h / 2; y++)
    for (x = 0; x < w / 2; x++)
    {
        nErrcount = IG_DIB_pix_get(hImage, x, y, &hPix);
        for (c = 0; c < nChannels; c++)
        {
            IG_image_channel_depth_get(hImage, c, &nDepth);
            nDepth = (1 << nDepth) - 1;
            inverted = nDepth - IG_pixel_value_get(hPix, c);
            IG_pixel_value_set(hPix, c, inverted);
        }
        nErrcount = IG_DIB_pix_set(hImage, x, y, hPix);
        IG_pixel_delete(hPix);
    }
nErrcount = IG_save_file(hImage, "test.bmp", 
    IG_SAVE_BMP_UNCOMP);
IG_image_delete(hImage);

Remarks:

The pixel data is contained by a pixel object with handle of type HIGPIXEL. This pixel object stores values for each channel in the image.