Operator DmaFromPC

The operator DmaFromPC provides a source for image data from the PC, e.g. when the frame grabber is used as a co-processor, or well defined test images should be fed into the processing pipeline.

All data received by a DMA from the PC memory are output at the output link O. The format of the output link can be selected from 6 gray scale and color formats accessible via the parameter LinkFormat.

Because the data stream send from the PC memory does not support image dimensions, the size of the frame has to be defined using the parameters MaxNumPixel and MaxNumLines. Mind that the number of bytes transferred via DMA must match the image dimension calculated from these two parameters.

Although the parameters MaxNumPixel and MaxNumLine allow to define extremely large images there are some restrictions to observe. First of all the image size is not allowed to extend 2 Gbyte. The second restriction is that the parameter MaxNumPixel must be set in multiples of the output link parallelism.

This operator requires one VisualApplets resource of type DMA. Set the resource index for the camera in the resource dialog. Check 'Allocation of Device Resources' for more information.

Available for Hardware Platforms
microEnable IV VD-CL/-PoCL

I/O Properties

Property Value
Operator Type M
Output Link O, image data output

Supported Link Format

Link Parameter Output Link O
Bit Width auto1
Arithmetic {unsigned, signed}
Parallelism 4
Kernel Columns 1
Kernel Rows 1
Img Protocol {VALT_IMAGE2D, VALT_LINE1D, VALT_PIXEL0D}
Color Format auto2
Color Flavor auto3
Max. Img Width any
Max. Img Height any

1

The input bit width is defined by parameter LinkFormat.

2 3

The color format and color flavor is defined by parameter LinkFormat.

Parameters

MaxNumPixel
Type dynamic read/write parameter
Default 1024
Range [1, 65536]

This parameter defines the width of the transferred image in pixels. The value has to be less than the link property Max. Image Width.

MaxNumLines
Type dynamic read/write parameter
Default 1024
Range [1, 65536]

This parameter defines the height of the transferred image in lines. The value has to be less than the link property Max. Image Height.

LinkFormat
Type static parameter
Default GRAY8x4
Range {GRAY8x4, GRAY16x2, GRAY32x1, RGB8x1, RGB8x2, RGB16x1}

This parameter specifies the data format of the output link O. Available formats are:

GRAY8x4 gray scale image, 8 bit per pixel, parallelism = 4
GRAY16x2 gray scale image, 16 bit per pixel, parallelism = 2
GRAY32x1 gray scale image, 32 bit per pixel, parallelism = 1
RGB8x1 RGB color image, 8 bit per pixel, parallelism = 1
RGB8x2 RGB color image, 8 bit per pixel, parallelism = 2
RGB16x1 RGB color image, 16 bit per pixel, parallelism = 1

Examples of Use

The use of operator DmaFromPC is shown in the following examples: