IG_IP_rotate_any_angle

This function rotates the image by the specified angle.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_IP_rotate_any_angle_ex( HIGEAR hIGear, DOUBLE angle, AT_MODE rotate_mode, LPAT_PIXEL lpBkgrndColor, AT_MODE interpolation );

Arguments:

hIGear	HIGEAR handle of image.
angle	Angle by which to rotate the image, in degrees. Positive values result in clockwise rotation; negative values result in counter-clockwise rotation.
rotate_mode	Rotation mode. Specifies whether the image should be clipped or expanded. See enumIGRotationModes for possible values.
lpBkgrndColor	A far pointer to the RGB or pixel value that specifies the background color to be used in the displaced areas after the image has been rotated.
interpolation	Interpolation to use for rotation. Supported modes are IG_INTERPOLATION_NONE, IG_INTERPOLATION_BILINEAR, IG_INTERPOLATION_BICUBIC. Ignored for 1-bit images.

Return Value:

Returns 0 if successful. Otherwise, returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

If interpolation is IG_INTERPOLATION_BILINEAR or IG_INTERPOLATION_BICUBIC:

All pixel formats supported by ImageGear Professional, except:

Indexed RGB with non-grayscale palette.
Images that have a Grayscale LUT attached to them.

Otherwise, all pixel formats supported by ImageGear Professional.

Interpolation mode is ignored for 1-bit images.

Sample:

See GUI component source code.

Example:

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HIGEAR hIGear; // HIGEAR handle of the image AT_ERRCOUNT nErrcount; // Count of errs on stack upon ret from func AT_INT channelCount; // Count of channels in the image AT_PIXEL lpBackground[256]; // Buffer for background color AT_INT i; // Load image file "picture.bmp" from working directory nErrcount = IG_load_file("picture.bmp", &hIGear); if(nErrcount == 0) { // Get channel count IG_image_channel_count_get(hIGear, &channelCount); // Initialize background color with '255' for(i = 0; i < channelCount; i ++) { lpBackground[i] = (AT_PIXEL)255; } nErrcount = IG_IP_rotate_any_angle_ex(hIGear, 45., IG_ROTATE_CLIP, lpBackground, IG_INTERPOLATION_BILINEAR); // ... // Destroy the image IG_image_delete(hIGear); }

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HIGEAR hIGear;            // HIGEAR handle of the image
AT_ERRCOUNT nErrcount;    // Count of errs on stack upon ret from func
AT_INT channelCount;    // Count of channels in the image
AT_PIXEL lpBackground[256];    // Buffer for background color
AT_INT i;

// Load image file "picture.bmp" from working directory
nErrcount = IG_load_file("picture.bmp", &hIGear);
if(nErrcount == 0)
{
    // Get channel count
    IG_image_channel_count_get(hIGear, &channelCount);
    // Initialize background color with '255'
    for(i = 0; i < channelCount; i ++)
    {
        lpBackground[i] = (AT_PIXEL)255;
    }
    nErrcount = IG_IP_rotate_any_angle_ex(hIGear, 45., IG_ROTATE_CLIP, lpBackground, IG_INTERPOLATION_BILINEAR);
    // ...
    // Destroy the image
    IG_image_delete(hIGear);
}

Remarks:

The function rotates the image about its center point.

You can use IG_IP_rotate_compute_size to calculate the new dimensions of the bitmap that the image will have after rotation in IG_ROTATE_EXPAND mode.

For the highest quality, bilinear interpolation is recommended, especially if the rotation angle is small (less than 5 degrees) and/or the image will be rotated multiple times. Bi-cubic interpolation can be used to achieve a slightly sharper appearance.

Rotating the image multiple times at angles that are not multiple of 90 degrees may degrade the quality of the image.

You can only rotate PDF/PS images in 90 degree increments.

ImageGear Professional DLL v17.1 for Windows
IG_IP_rotate_any_angle_ex
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