An image taking apparatus, which can reduce the power consumption of the total system of the image taking apparatus without deteriorating image quality when an image is displayed on a liquid crystal display (LCD), is provided. In the image taking apparatus, the quantization bit number at an analog to digital (A/D) converter and the signal processing bit number at a digital signal processor (DSP) are variable. With this, at an LCD displaying mode that video signals are displayed on the LCD, the quantization bit number at the A/D converter is reduced and also the signal processing bit number at the DSP is reduced to the same bit number at the A/D converter. With this operation, at the LCD displaying mode, the power consumption at the A/D converter and the DSP is reduced, therefore the power consumption of the total system of the image taking apparatus is largely reduced.