Scaling device and method capable of controlling data flow quantity

• US 8,792,749 B2
• Filed: 09/16/2004
• Issued: 07/29/2014
• Est. Priority Date: 09/16/2003
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Ou, Hsin-Ying, Chang, Hui-Huang, Chang, Chia-Pei
• Primary Examiner(s): TSAI, TSUNG YIN
• Application Number:
  US10/942,183
• Publication Number:
  US 20050058370A1
• Time in Patent Office: 3,603 Days
• Field of Search: 382/298
• US Class Current: 382/298
• CPC Class Codes: G06T 2200/28 involving image processing hardware
• CPC Class Codes: G06T 3/4084 in the transform domain, e.g. fast Fourier transform [FFT] domain scaling

Abstract

A scaling device for receiving and scaling a digital image signal includes a scaling module and a data quantity control logic. The scaling module scales the digital image signal and then outputs a scaled output signal according to a scaling ratio. The data quantity control logic controls output quantity of the scaled output signal according to a scaling ratio. Thus, when the data quantity outputted from the scaling module is controlled within the data quantity that may be processed by the post stage of the scaling module per unit time, the data quantities that may be processed per unit time in the post stage processing devices of the scaling module approximate a constant value such that the post stage processing speed of the scaling module may be increased.

Claims

1. An apparatus for scaling a digital image signal comprising a plurality of data rows, the apparatus comprising:

a scaling module for scaling the digital image signal and outputting a scaled output signal according to a scaling ratio;

at least one image processing unit, coupled to the scaling module for receiving the scaled output signal and processing the scaled output signal to produce a processed image signal, wherein the at least one image processing unit has a maximum processing quantity per unit time; and

a data quantity control logic, coupled to the scaling module for adjusting a number of the data rows in the digital image signal to be inputted to the scaling module according to the scaling ratio such that an output quantity of the scaled output signal per unit time of the scaling module is smaller than or equal to the maximum processing quantity per unit time of the at least one image processing unit.

2. The apparatus of claim 1, wherein the data quantity control logic adjusts the number of the data rows of the digital image signal inputted to the scaling module to optimize processing speeds of the scaling module and the at least one image processing unit.

3. The apparatus of claim 1, further comprising:

a memory, which is coupled to the scaling module and the data quantity control logic, for outputting the digital image signal;

wherein the data quantity control logic controls the memory to output the number of the data rows of the digital image signal to the scaling module based on the scaling ratio.

4. The apparatus of claim 3, wherein the data quantity control logic comprises a direct memory access logic (DMA Logic).

5. The apparatus of claim 1, wherein the data quantity control logic comprises a DMA Logic, and the DMA logic controls the number of the data rows of the digital image signal inputted to the scaling module based on the scaling ratio.

6. The apparatus of claim 1, wherein the at least one processing unit comprises a first image processing unit and a second image processing unit, and processing speeds of the first and the second image processing units are substantially the same.

7. The apparatus of claim 1, wherein the at least one processing unit is selected from a group of a color processing device, a halftone processing device, a filtering device, and a data format processing device.

8. The apparatus of claim 1, wherein the apparatus for scaling the digital image signal is used in a system without requirement of external memory which is used for storing the scaled output signal.

9. The apparatus of claim 1, wherein the data quantity control logic adjusts the number of the data rows of the digital image signal inputted to the scaling module such that the output quantity of the scaled output signal per unit time of the scaling module is maintained.

10. A method for scaling a digital image signal comprising a plurality of data rows, the method comprising:

producing a control signal according to a scaling ratio;

adjusting a number of the data rows in the digital image signal to be scaled based on the control signal;

receiving the number of the data rows of the digital image signal, and scaling the number of the data rows of the digital image signal according to the scaling ratio to output a scaled output signal; and

processing the scaled output signal by at least one processing unit to produce a processed image signal;

wherein the number of the data rows in the digital image signal to be scaled is adjusted such that the output quantity per unit time of the scaled digital signal is not more than a processing quantity per unit time of the at least one processing unit.

11. The method of claim 10, wherein receiving the number of the data rows of the digital image signal is made by way of direct accessing.

12. The method of claim 10, wherein the step of processing the scaled output signal comprises first and second image processing procedures, wherein processing speeds of the first and the second image processing procedures are substantially the same.

13. The method of claim 10, wherein the method is used in a system without requirement of external memory which is used for storing the scaled output signal.

14. An apparatus for scaling a digital image signal comprising a plurality of data rows, the apparatus comprising:

a first circuit for outputting the data rows of the digital image signal;

a scaling module, coupled to the first circuit for scaling the data rows of the digital image signal and outputting a scaled output signal according to a scaling ratio;

at least one image processing unit, coupled to the scaling module for receiving the scaled output signal and processing the scaled output signal to produce a processed image signal;

a data quantity control logic, coupled to the scaling module for adjusting a number of the data rows in the digital image signal to be scaled according to the scaling ratio such that the output quantity per unit time of the scaled digital signal is not more than a processing quantity per unit time of the at least one processing unit

15. The apparatus of claim 14, wherein the apparatus for scaling a digital image signal is used in a system without requirement of external memory which is used for storing the scaled output signal.

16. The apparatus of claim 14, wherein the first circuit comprises a memory and the data quantity control logic comprises a direct memory access logic for d6irect accessing the memory.