Sony TX7 has a
10.0MP 1/2.4-inch (6.104 x 4.578 mm ) sized BSI-CMOS sensor and features Bionz processor. On the other hand, Sony TX100V has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor.
Sony TX100V's sensor provides 6MP more than Sony TX7's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the TX7 and TX100V sensor size comparison.
Sony TX7 and Sony TX100V have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.