ChangeViewPerspective Method (original) (raw)
Summary
Rotates and flips the image data as necessary to achieve the desired view perspective.
Syntax
C#
Objective-C
C++/CLI
Java
Python
- (BOOL)changeViewPerspective:(LTRasterViewPerspective)viewPerspective error:(NSError **)error Parameters
viewPerspective
Desired view perspective.
Example
This example demonstrates the low-level methods for accessing 1-bit compressed image data. It demonstrates the ability to get and put rows, and the ability to process rows in buffer-to-buffer processing. The result of the function is an the first 50 lines are inverted.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Core;
using Leadtools.ImageProcessing.Color;
using Leadtools.Dicom;
using Leadtools.Drawing;
using Leadtools.Controls;
using Leadtools.Svg;
public void GetRowCompressedExample()
{
RasterCodecs codecs = new RasterCodecs();
// Load the bitmap, at 1 bit per pixel, compressed
codecs.Options.Load.Compressed = true;
RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "OCR1.TIF"), 1, Leadtools.Codecs.CodecsLoadByteOrder.Bgr, 1, 1);
// This example does not work with rotated view perspectives.
if ((image.ViewPerspective != RasterViewPerspective.TopLeft) || (image.ViewPerspective != RasterViewPerspective.BottomLeft))
image.ChangeViewPerspective(RasterViewPerspective.TopLeft);
// Adjust the YOffset if the view perspective is bottom left.
int nRow = 500; // first row to get.
int nYSize = 500; // number of rows to get.
if (image.ViewPerspective == RasterViewPerspective.BottomLeft)
nRow = image.Height - nRow - nYSize;
// Allocate the buffers.
byte[] pBuffer = new byte[Convert.ToInt32((((image.Width + 31) & ~(31)) / 8)) * nYSize]; // Buffer to hold the expanded row.
ushort[] pRunBuffer = new ushort[((image.Width + 3) * 2) * nYSize]; // Buffer to hold the compressed row.
if (image.IsGlobalMemory)
image.Access();
// Get the top nRow lines.
image.GetRowCompressed(null, pRunBuffer, 0, nRow, nYSize);
// Expand the compressed data.
RasterRleCompressor.ExpandRows(pRunBuffer, pBuffer, 0, image.Width, nYSize);
// Invert the data.
for (int n = 0; n < (image.BytesPerLine * nYSize); n++)
pBuffer[n] ^= 0xff;
// Compress the inverted data.
RasterRleCompressor.CompressRows(pRunBuffer, pBuffer, 0, image.Width, nYSize);
// Put the inverted, compressed data back into the image.
image.SetRowCompressed(null, pRunBuffer, 0, nRow, nYSize);
if (image.IsGlobalMemory)
image.Release();
codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "IMAGE1_getrowcompresed.BMP"), RasterImageFormat.Bmp, 0);
image.Dispose();
codecs.Dispose();
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images";
}
Leadtools Assembly